Year 2000 MR2 roadster, UK version

[tperry2x]

Ok, I feel a little better about mine. It's had good service history and oil filter is brand new so the seller's info about keeping on top of oil changes might ring true. According to the log book, I'm the 9th keeper. The colour of the oil is light golden, so very clean.

[Call the midlife!]

Ok, I feel a little better about mine. It's had good service history and oil filter is brand new so the seller's info about keeping on top of oil changes might ring true. According to the log book, I'm the 9th keeper. The colour of the oil is light golden, so very clean.

All sounds good then, one things for certain you've come to the right place for help and advice, even if some of it is dodgy [emoji23]


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[smarty72]

Ok, I feel a little better about mine. It's had good service history and oil filter is brand new so the seller's info about keeping on top of oil changes might ring true. According to the log book, I'm the 9th keeper. The colour of the oil is light golden, so very clean.

All good signs but I understand your fear that engine detonation might be just around the corner while the ticking time bombs are still in situ.

Of course, with that many previous owners, someone may have already beaten you to removing them.

[Peter Wright]

Numbers on the ECU are as follows (line by line)
89221-17040
232300-0191

They are UK numbers
I have a JOBD/OBD11 reader here in Norwich if you want the ECU read
Pete

[tperry2x]

Fingers crossed. Mrs has just come home with a takeaway, so might not do it tonight after all   s:D s:D

Thanks Pete, sounds good. Much appreciated and I hope it's just a matter of clearing the codes since I did sensors and cleaned the MAF, but have to see.

[ilovejapcrap]

Is the precast really an issue ? Thought it was a bit of a myth to a degree ? They only cause problems if your burning oil which means the rings no ?

[tperry2x]

From what I understand, the ceramic of the precat breaks down over time and can get sucked back into the engine. This wears the rings down, causing slack and allowing engine oil blow-by, so then you start to see signs of oil / blue smoke.
Catalytic converters don't like oil so this can then clog the precats further, resulting in faster degradation. A vicious circle.
Think I've got the gist of it there.
If you sometimes get the smell of eggs from the exhaust, can mean the catalyst material is breaking down and not absorbing harmful chemicals in the exhaust gases anymore (although think it can be down to also what fuel is used and air/fuel mixture ratio).

[tperry2x]

The only specs I can find about JOBD readers is that technically they are similar to OBD2, but additionally support the Japanese standard (hence the J), and are a standard OBD2 port shape connection with an identical number of pins.
Thanks for the kind offers of loaning me a reader, although I'd really love to have my own.
I've got this on order (should arrive today at some point)
https://www.amazon.co.uk/dp/B07476GPYB/
It's the bit that says the JOBD format and 8 Japanese makes that makes me hopeful. If not, it'll go back for a full refund like the other two have done.

[smarty72]

That's not quite as I understand the issue.

I believe the problem is generally considered to stem from the poor design of the oil control ring, which without regular oil changes is likely to get gummed up and stick  in its groove.

This leads to oil consumption, the oil consumption issue is what leads to the break down of the pre cat issues.

So, if your engine doesn't burn any oil you're probably completely safe.

If your engine burns a bit of oil, it's best to remove the pre cats, and your engine should be good for many more miles.

Leaving the pre cats in an engine consuming oil will be likely to end in tears.

Someone may well be along and correct me, but that is my understanding of the issue.

[smarty72]

Although I believe 'oval bore syndrome' is pretty much considered a myth nowadays!

[tperry2x]

Oh, ok. That's great to know and very reassuring- thank you. I'm of the school of thought that if they aren't fitted, they can't go wrong. Either way, they are definitely coming out as soon as I get the chance.
I'll update this post on the findings of the JOBD reader when it arrives if
A: it connects, B: finds anything, C: flags up codes
Fingers crossed.

[tperry2x]

Ok, so here's where I'm up to:

1. Greased all the nuts I thought I'd have to undo thoroughly


2. Using the special O2 socket, the left-hand side one came undone no problem.


3. The right-hand side one needed more persuasion!


4. The O2 sensors probably shouldn't look like this:


5. Cleaned them up:


6. With the sensors out, can't see any precat at all. Think this means it's been done already by one of the previous 8 owners:


7. Now on to the JOBD reader:


8. Connects! Success. Only through JOBD mode, won't connect through OBD2 mode. Brings up 6 errors. The only 2 that are current are these two (The other 4 were historic):

Error 1: (Current - P0135 Oxygen Sensor Heater Circuit, Bank 1 Sensor 1)
Error 2: (Current - P0155 Oxygen Sensor Heater Circuit, Bank 2 Sensor 1)
Error 3: (Historic - P0000 ISO/SAE Reserved)
Error 4: (Historic - P0000 Fault code not found in database)
Error 5: (Historic - P0135 Oxygen Sensor Heater Circuit, Bank 1 Sensor 1)
Error 6: (Historic - P0155 Oxygen Sensor Heater Circuit, Bank 2 Sensor 1)


So this seems to indicate my main cat sensor is ok, it's the left and right ones which have both failed.

8. JOBD reader won't allow me to clear the codes though, so it's not fully compatible   s:evil: :evil: s:evil:  :


This is at least a lot further ahead than I was yesterday.
Thinking about seeing if the reader can be updated, but I haven't got a Windows PC (everyone I know is Mac), so will have to beg someone for the loan of their Windows PC.

[delhusband]

Thanks for posting that schematic of O2 sensors - gave me double confirmation of the reason for a recent Issue I had with a p0171 error (I'd forgotten to plug O2 1/1 back in after doing what you're doing right now, checking if precats were there or not  s:oops: :oops: s:oops: )
Can I ask what you cleaned O2 sensors with?

[tperry2x]

Delhusband: glad this rambling post has helped someone. I cleaned the sensors with a rag, nothing special. No solvent / petrol or anything for fear of messing them up.
(Too late I think).
 
Still looking for a JOBD reader for a UK, year 2000 car though. Don't want to have to take it to an expensive garage, but might give them a call and see if they are feeling generous, lol.

[Treboeth]

Is that the same reader that PeterWright has, maybe worth a visit and a chat with him anyway.

[tperry2x]

Would be worth a try before I go the expensive route.

[Treboeth]

When someone offers help on here jump in and grab it, you will probably learn 4 or 5 other interesting things as well   s:D s:D  


Disclaimer for the bolded part
This may end up either saving you money or costing you more by giving you the moditis bug   s:lol: :lol: s:lol:

[shnazzle]

Bit late to the party but welcome  s:) s:)

Few things;
1) That red box is your ABS control module. Not the ecu. The ecu sits behind your passenger cubby hole.
2) you need your o2 sensors. All of them. O2 sensors have a (admittedly long) lifespan in which the function well. No code for the o2 does not mean they're all good. Heater circuit tricking is fine.
3)If you have the 3rd sensor (in your cat) then it's not a JDM car (Japanese import). So, I'm a bit confused about it needing to be read by a JOBD reader. So, bit lost on that one. Sure someone else can shed some light.
4) No visible pre-cats can be a good and a bad thing. In your case, as the oil is clear and car runs well, probably a good thing but they have been known to be fully collapsed and clogging up main cats.
5) ecu part numbers for that year should be 89661-17610 but it sounds like yours is 89661-17650. Again, very confusing. Can you try unplugging the o2 sensor in the cat (behind left rear light) and see if that throws any code? If not....ecu had been switched for a JDM one.
6) if you took the neg battery cable off for 30 mins, it should clear your ecu. Codes coming back as live codes are not the ecu pulling stuff out of memory. It'd the ecu saying it has found reasons to throw those codes  s:) s:)  so, the issues are still there.

[tperry2x]

Thanks shnazzle. Great information - I'll get back to you...

[Carolyn]

As Shnazzle said, if you have an O2 sensor at the main cat, it's not JDM and requires a European OBD (OBDII) reader.  If no main cat sensor, OBDMATE make an inexpensive JOBD reader.

[tperry2x]

I'm always up for learning new things, I'm new to this car and there's always something to get my head around. Didn't mean to sound like I was shunning anyone's help, so sorry Pete and Treboeth - didn't mean to come across that way.

Shnazzle - gone through a few things you suggested.
1. Do you mean behind passenger seat, that cupboard as can't see anything ECU related there, neither behind or tucked under glove box. Feel like I'm not looking in the right place then, oops.

2. So what I've done with the heater circuits and resistors are ok?

3. The reader just fails to communicate on the OBD2 setting, but under JOBD, enters the scanning mode fine.

4. If the main cat was clogged, I'd assume a loss of power, but it pulls fine in all gears through the rev range.

5. Here's where it gets weird; unplugged the connector of sensor you mentioned, leading to the bottom post cat. Turned ignition on with reader attached and heard what can best be described as a high pitch squealing. Not like the buzzer when you've left your lights on. Much higher pitch. The reader won't connect at all or talk to the car with this sensor unplugged. Plugged it back in and all was just as it was before, but now I can erase codes without an error.
The reader said codes cleared, but engine light is still on. When I chose to read the codes again, they are still there, even the historic ones.

6. Left battery off for 30 mins. Put it back on and engine light is off. Drove to work this morning and about half way there, light comes back on. Plugged in the reader again and it's exactly the same, with the historic codes showing too.

So, I'm a bit stumped right now. Need to identify the ECU if I could find it. Would it be as simple as putting a more recent ECU in to make it more compatible?

The reader can do JOBD, OBD2 and 3 others (haven't got the packaging with me right now, so couldn't tell you). Says it should work with everything after 1996.

[Call the midlife!]

Bit late to the party but welcome  s:) s:)

Few things;
1) That red box is your ABS control module. Not the ecu. The ecu sits behind your passenger cubby hole.
2) you need your o2 sensors. All of them. O2 sensors have a (admittedly long) lifespan in which the function well. No code for the o2 does not mean they're all good. Heater circuit tricking is fine.
3)If you have the 3rd sensor (in your cat) then it's not a JDM car (Japanese import). So, I'm a bit confused about it needing to be read by a JOBD reader. So, bit lost on that one. Sure someone else can shed some light.
4) No visible pre-cats can be a good and a bad thing. In your case, as the oil is clear and car runs well, probably a good thing but they have been known to be fully collapsed and clogging up main cats.
5) ecu part numbers for that year should be 89661-17610 but it sounds like yours is 89661-17650. Again, very confusing. Can you try unplugging the o2 sensor in the cat (behind left rear light) and see if that throws any code? If not....ecu had been switched for a JDM one.
6) if you took the neg battery cable off for 30 mins, it should clear your ecu. Codes coming back as live codes are not the ecu pulling stuff out of memory. It'd the ecu saying it has found reasons to throw those codes  s:) s:)  so, the issues are still there.

I was confused about the ECU location too, was 99% confident it was in the cubby but waiting for someone else more betterer to come along and say it!


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[Call the midlife!]

I'm always up for learning new things, I'm new to this car and there's always something to get my head around. Didn't mean to sound like I was shunning anyone's help, so sorry Pete and Treboeth - didn't mean to come across that way.

Shnazzle - gone through a few things you suggested.
1. Do you mean behind passenger seat, that cupboard as can't see anything ECU related there, neither behind or tucked under glove box. Feel like I'm not looking in the right place then, oops.

2. So what I've done with the heater circuits and resistors are ok?

3. The reader just fails to communicate on the OBD2 setting, but under JOBD, enters the scanning mode fine.

4. If the main cat was clogged, I'd assume a loss of power, but it pulls fine in all gears through the rev range.

5. Here's where it gets weird; unplugged the connector of sensor you mentioned, leading to the bottom post cat. Turned ignition on with reader attached and heard what can best be described as a high pitch squealing. Not like the buzzer when you've left your lights on. Much higher pitch. The reader won't connect at all or talk to the car with this sensor unplugged. Plugged it back in and all was just as it was before, but now I can erase codes without an error.
The reader said codes cleared, but engine light is still on. When I chose to read the codes again, they are still there, even the historic ones.

6. Left battery off for 30 mins. Put it back on and engine light is off. Drove to work this morning and about half way there, light comes back on. Plugged in the reader again and it's exactly the same, with the historic codes showing too.

So, I'm a bit stumped right now. Need to identify the ECU if I could find it. Would it be as simple as putting a more recent ECU in to make it more compatible?

The reader can do JOBD, OBD2 and 3 others (haven't got the packaging with me right now, so couldn't tell you). Says it should work with everything after 1996.

The "passenger cubby hole" is behind the passenger seat, take the end trim panel off and you should see the ECU wrapped in plastic. If you've got the user manual it should describe how to remove the end panels to carry long objects...


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[shnazzle]

Don't think you were shunning anybody's help  s:) s:)  This is how it goes. We are/were all new to the game and it's a learning experience all the time! Makes it fun  s:) s:)

1. Yes in the cupboard. Well, behind it. So you have to remove the door (3 bolts), remove the two bolts that hold down the bottom of the cubby. Remove the right side plastica (two pull-clips). And then remove the bottom. Behind the material you'd then spot the silver ecu hidden behind a black security barrier, held on by two 5-point security torx screws.
A picture would be very handy.

2. Sounds like it's still getting an incorrect voltage from that heater circuit, as it's still throwing the p0155 and p0135. Easiest is of course to replace the sensors.

3. Really puzzling... I'm still standing by an ECU switch... Somehow.

4. It is unlikely, it was more an FYI. it seems more likely that your cats have been removed and all is good.

5. I don't even know where to go with that... That's.. Unusual... I'm definitely going to be doing some reading. Hell, I might Unplug mine and see what it does.

6. The clearing definitely works. It's just that the codes are still being found. So the resistor fix isn't working. Are you passing both sensors through the same resistor? If so, try one and see if one of the codes drops away.

This could do with a trip to the likes of headcase (Patrick Chambers) or our guru Steve at D1 Customs. Or Carolyn. Or a handful of others willing to help  s:) s:)

[Carolyn]

This is strange.  I have run a Europe spec engine and harness on a JDM (JOBD) ECU, with the main cat sensor disconnected.  I'm told that a euro spec ECU won't be happy on a JDM harness, but I haven't tried that one.
The fact that your reader is happy with the ECU on JOBD, tells me the ECU should not even be looking for a main cat sensor, and, anyway, there is no connector for that sensor on a JDM harness. So you have a Euro spec harness.  I wonder if you also have a Euro spec engine?  
So... probably.. either your reader is not working properly or your ECU is playing up, or you've made a wiring error and it's confusing everything.
Take out all the plastics for the bin behind the passenger seat, the ECU is attached to the bulkhead by five point torx screws.
Question:  Does your car have a built in (operated by a two button key) immobilser?  If it does, it's Euro spec, if not it's JDM.
As suggested, time for a more expert eye in this one?