Severe Power Loss & Loud Engine (there is some history)

[Graeme]

Hi there,

Although I love my new (new to me) MR2, it is proving to be quite a troublesome car. Nothing like my old focus (although that was boring  s:roll: :roll: s:roll:  ). I thought Japanese cars were menat to be reliable.

The History: The CEL came on about a week after I bought it (privately) so I took it to MrT and he read the code for free  s:) s:)  . It was P0175 - System too Rich (Bank 2). He reset the light, but it came back on a couple of days later. I was broke for a month or two as I'd just bought the car, so I thought that this was a minor malfunction and I'd sort it later.

I took it back in and they re-read the code, this time P0172 & P0175 - System too Rich (Bank 1 & 2). This time they said it was the o2 sensors gone wrong and they would order some in and then they booked the car in for the 10th Jan 2007. They re-set the code, but back on almost instantly.

I read on the forums (here) about these codes and one sugesstion was to clean the MAFF with carb cleaner, so I did this and re-set the ECU (disconnected the battery for 30 mins) and all seemd fine for about 200-250 miles. I was so pleased that I was about to donate a substantial sum to the MR2ROC as MrT were about to charge me £262 to replace two parts that was not even faulty

Today: About 50 miles into my journey towards my Gran's for Boxing Day, the engine became a little louder and suffered a loss of power (I thought I was driving into some crazy-strong headwind). Now (about another 100 miles on - I had to get back home) it doesn't like pulling away and will not accelerate hardly at all uphill. It makes all the normal (I'm accelerating hard) sounds, but a bit louder, but with my foot to the floor, there is nothing  s:cry: :cry: s:cry:  .

The clutch is not slipping, and the CEL is not on. I have not checked anything else, but I will soon be checking/removing the precats

Does anyone have any suggestions as to a possible cause/solution for this as I fear MrT will charge me a lot to diagnose/repair?

Thanks Guys/Girls

Graeme

[Anonymous]

Possibly not related to your O2 problems, but have you checked the pre-cats at all? It's just that loud engine + foot down but going nowhere usually points to this...  s:( s:(

[Graeme]

Possibly not related to your O2 problems, but have you checked the pre-cats at all? It's just that loud engine + foot down but going nowhere usually points to this...  s:( s:(

Great!  s:lol: :lol: s:lol:  I kinda thought that from reading a few similar posts. I'm at work tomorrow, but I'll try to get on it tomorrow evening.

Edit: I can't check it tomorrow as I don't have a 22mm o2 socket   s:x :x s:x  . Just ordered one so it should be with me on Thursday/Friday (assuming gendan work over this period) -  Any other ideas from anyone of what to check while that is on the way?

Cheers

Graeme

[rtbiscuit]

lots of noise, engine sounds normnalish but no power is generally down to a blocked exhaust somewhere along the line.

check for any dents in the boxes, my guess is you won't find any,

the likely answer is your precats have gone a chunk is now sat in the way of you main cat.

this blockage reduces the exhaust gas flow, and the ECU adjusts to protect the engine, hence the loss of power.

my advice would be not to drive the car, as its possible that the reason your precats have gone is because the o rings have gone in the piston chambers (or something to the like, someone else can explain better) this will then mean oil will leak into the precats etc etc.

it is possible the more you drive the more expensive the damage

worst case senario is a new engine (but on the plus side you could upgrade to a 2zz with 190 bhp)

if caught early it could be new o rings.

basically checking your precats will give you an idea, but i would also remove the cat and see if it is bloked.

even better take to mr T and guide them in this direction.

i hope i'm on the right lines, im i'm wrong someone will most probably correct me.

i hope this is a wallet friendly incident, and best luck with the car.  s:cry: :cry: s:cry:

[Liz]

Nice write up Richard - you could of saved some typing though  s:wink: :wink: s:wink:   - the official pre-cat thread is here:

 m http://www.mr2roc.org/phpBB2/viewtopic.php?t=11393 m

Good luck Graeme - my car is not running 100% at present and it is annoying.

[darrenjuggins]

Hi,

another option could be a MAF that has died, I've had both the engine replacement, cat replacement and pre cat replacement as well as MAF replacement.

The MAF issue caused the engine to feel flat in the rev range, similar to the experience I had with the engine failure (i'll not call it pre-cat failure, as I believe mine was oval bores, leading to all cat failure, chick/egg senario).

Anyhow, having the MAF replaced, made everything good again, but unfortuately, any or all of the above, MAF, CAT, engine Bores, etc, etc, unfortunately all cost money.......

Good luck and I hope you get it sorted...

Cheers

Darren J

[Anonymous]

check your oil as well.

 Low oil wont be the cause in itself but would be a sign that you have bore wear, which if your precats have gone will be a bad sign.

goodluck

[Graeme]

check your oil as well.

Done, the level is about the same height as it was about 350 miles ago. At least that's a good sign.

The car is now off the road until it is fixed. My kind parents have offered to drive me in & out of work for at least the next two days.

goodluck

Thanks

Graeme

[rtbiscuit]

if the oil level hasn't changed then it is possible that your piston rings are fine.

it could just be the precats, and their is a CHE manifold group buy going at the mo. due in this coming month. you could clear out the precats temporarily, and then replace with the che.

but either way it is possible the main cat will have to be changed.

if doing this my advice is go for a sports cat, and have that welded in, works out to a similar price.

but get it checked by mr t first to see what the problem is!

[Graeme]

Hi all,

Well my o2 sensor socket came through, and after having my dinner, i set to work removing the sensors to take a peek at the precats. Left one looks fine, right one is nowhere to be seen, and when pushing in a plastic rod until there is any resistance - there is none.   s:D s:D  (left and right as in looking from behind the car).

It seems like I shouldn't be happy about this, but the car doesn't seem to be losing any oil, so hopefully I may have gotten away with it.  s:) s:)  

I haven't taken the manifold off yet as it's too dark, and I don't have a replacement gasket. Hopefully MrT stocks them so I can pick one up tomorrow.

One last question though: The two bolts that hold on the heat shield on top of the manifold are very rusted (as in the heads are now about 11mm and circular). What is the best way to remove them  s:?: :?: s:?:  


Thanks
Graeme

[rtbiscuit]

my advice is not to replace the precats, it will just happen again later down the line.

clean out the ones you have, put it back on until you buy a Che manifold or not, thats down to personal preference.

what you wil have to pay out for possibly is a new main cat, although you might be lucky and you can dislodge the blockage, but i'm unsure on this.

if your oil is fine you should be ok.

and as said above if you need a new main cat have a look at universal sports cats, had one fitted to my pug, and the cost is very similar.

[Anonymous]

You now need a brand new cat (not optional) and to gut your existing manifold.

Don't worry about the bolts on the top of the heatshield, as they're easy to replace if you break one, and besides you don't have to put the shield back on anyway: I (and many others) never bothered so dremel the head off if you like, or dremel a slot in it and try a screwdriver. Read the gutting instructions in the pre-cat thread for what to do next, although you'll obviously also need to replace the cat as well but that's obvious what to do when you're down there. Lots of Plusgas everywhere and a bit of heat (blowtorch, not hairdryer  s;) s;) ) will probably help you as well.



Oh, and it might be worth a prayer about now.  s;) s;)   Good luck mate!

[Graeme]

You now need a brand new cat (not optional) and to gut your existing manifold.

Is that definately not optional? Couldn't I just clean it out with a pressure cleaner until I get a replacement one. I know I'll probably need a new one for my MOT (which is coming up soon)

Good luck mate!

Thankyou

Graeme

[Anonymous]

Pressure cleaning it is no good really, as you've no guarantee that you've got all the microscopic bits of pre-cat out of the main cat, and then they get sucked back into your engine and then you're really screwed. I'd personally rather pay a few hundred quid for a new cat than a thousand for a new engine.  s;) s;)

[Graeme]

OK. So I'm going to need a new main cat (Enid_b has one for sale I think. I've PM'd him), and a replacement gasket between the manifold & engine.

Will I need anything else? eg. a gasket between manifold & exhaust or anything to fit the main cat? (specialist tools/gasket) etc.

Cheers
Graeme

[Anonymous]

No special tools really, but an assortment of sockets, ratchets and a breaker bar will come in handy. As for gaskets, you'll need the two mentioned in the pre-cat thread (between manifold and cat), and I'd get the one between manifold and block if it were me. Saying that, many people have gutted their pre-cats and re-used the existing one as it will be already crushed for your manifold. I'd still change it, but you don't have to.

I can't remember off-hand if there is a gasket between cat ad exhaust, but I should imagine there is. Try a search and see what comes up, if no-one else pipes up in here.

[Anonymous]

Yep there is a type of gasket between the cat and exhaust, it looks like a asbestos type material - but obviously not, the downside is they are about £30 so I would re-use the old one. You just need to be careful when taking it off the old unit.

Rob

[Anonymous]

This does not sound good. But a lucky few have survived past this stage so I'm sending my best wishes, Graeme.

Ekona is spot-on, here. The main cat must be replaced immediately. Here's why: In the classic precat death syndrome, the precat matrices degrade and crumble. The fine ceramic dust produced can enter the cylinders during valve overlap, particularly on motor shutdown. If any of it gets in there, cylinder-wall scoring results and then oil leakage leads to catastrophic failure. Repairs are no longer possible and the motor must be replaced.

The main cat has a number of vented baffles such that you can't simply shake the thing and hope the bad bits fall out. If any of the debris remains, it is a potential source of trouble. So pull off the header, the downpipe, the main cat. Clean the downpipe and either gut the header or replace it. Replace the main cat with stock or aftermarket. Replace all four gaskets (they're so cheap, why not?) and monitor oil consumption daily.

If no problems emerge after a few months or so, then you've dodged the bullet. Best of luck.

[Graeme]

Update:

Thanks for all the help and advice guys, I've gutted the remaining precat, and replaced the main cat with a second hand one from Jason (enid_b).

I did get a warning light come on after doing all that so roger come out of his way to meet me on Sunday morning a few miles from where I live (thanks again roger) with his OBDII reader which told me that the post cat o2 sensor heater circuit was faulty (P0141). I must have given it a knock when I was faffing about under the car. I ordered a generic replacement one from gendan yesterday and it arrived and got fitted today.

I've been on a very fun 45 mile drive tonight (with the top down in the rain - People were looking at me like I was a nutter, but I barely got a drop on me  s:) s:)  ) including 3 or 4 engine turn off and ons (I can't remember exactly) and the light has not come back on  s:D s:D  

So it looks like I may all be sorted (as long as I don't start losing oil, but I haven't noticed any yet in about 150 miles).

I've managed to get all this sorted for:

£9 - Carb Cleaner
£8 - o2 sensor removal socket
£5 - Plusgas
£218 - second hand cat + postage
£5 - Exhaust gasket
£14 - Manifold Gasket
-£10 - I got for my old cat for recycling  s:D s:D
£30 - o2 sensor

Total: £279 and a few evenings work.

Considering Mr.T was going to charge me £262 to change the two manifold o2 sensors originally which would not have solved anything, or left me with my own o2 tool, plusgas, or carb cleaner, I'm very pleased and would like to thank everyone who has helped with my problems.

I hope to meet you all soon at one of the club meets, but I can't make the 20th as I'll be in Italy snowboarding  s:D s:D  .

Thanks again Guys
Graeme

[Wabbitkilla]

Great news Graeme - well done!

Very happy that it didn't turn out for the worst, and Mr T didn't make an unacceptable profit for their ineptitude  s:wink: :wink: s:wink:

[enid_b]

nice work G. theres nothing like that feeling of DIY, and u also got the pleasure of sticking it to 'THE MAN'

enjoy the snow... missin my board already and its only 5 weeks since i went !

J

[Mason Storm]

Glad to hear all is OK

I had to get my cat replaced and gutted the pre cats.

If anyone else is in doubt if the cat is the problem you can get a mechanic to measure the heat coming out of the cat. This is what Silverstone Performance did when they checked my car out, they said my cat was registering more heat than the manifold which ment that the cat was blocked as there's no way this should happen otherwise.

My cars been fine ever since so hopefully your OK now.