Replaced o2 sensors with Walkers Universals, now getting...

[vatovey]

Evening all,

Middle of last week I replaced the standard o2 sensors with Walkers Universals as recommended by the How To... guide, all has been well up until last night when the CEL came on while steadily cruising at around 75mph  s:( s:(

I just did a diagnostic and it came back as P0171 x 2, and P0174.

Can I assume that these are related to the new o2 sensors ?

Cheers, Vaughn.

[Wabbitkilla]

 l viewtopic.php?f=46&t=12480 l

Did you reset the ecu at the same time as replacing them?

[vatovey]

nope, I didn't, but the CEL didn't come on until 4-5 days after installation.

[Wabbitkilla]

It's worth resetting the ecu anyway when you change the sensors to allow your ecu to relearn the correct fueling.

If it happens again a few days after that then it's possible you've got iffy sensors or there's another problem causing mis-fueling (like a dirty maf or air leak).
What were the codes that caused you to replace them in the first place?

[vatovey]

cool - i shall set about resetting the ECU this evening, is it a case of removing battery power for 10 mins or so in order to complete this ?

I initially had P0141 in my cat o2 sensor, but had MrT replace that under warranty a few weeks back.

When I had the original P0141 fault, I did clean the MAF then, i shall take another look though just incase.

As the car is nearly 10 years old, I thought it might be worth replacing the other two o2 sensors as many people say they should be replaced routinely after around 6 years of use, so I purchased a set of rubbish universals from a vendor on eBay - which didn't work, and brought up a CEL after an hours worth of driving, so I then purchased a pair of the Walker universals as the person in the How to guide recommended them and most importantly - they seemed compatible with the MR2, unfortunately, they to initiated a CEL light after 4-5 days worth of driving.

Does anyone have the wiring assignments for the Walker universals, mine came with exactly the same colours as my original sensors, so simply soldered the same coloured wires together.

[Wabbitkilla]

Sounds like the Walkers are OEM then ... I've got one on my car too.

Just disconnect the battery, some people say 20 minutes though, but i got away with less (when i was using the oem ecu).
It'll then recalibrate the fuel trims, you'll need to go out for a drive for a while until it gets it's settings in order though   s:wink: :wink: s:wink:

[vatovey]

ok - on Saturday (21st November 09) reset the ECU as per suggestion.

Went on a test run the same day, seemed ok.

Tested again last night, when cruising up to 70mph - everything seemed ok, as soon I pushed the speed up to 75mph the CEL came on, I haven't read the codes yet, but I suspect they are p0171 and p0174 as per previously.

I think I'm gonna have to put the original o2 sensors back to confirm that its definetely the new Walker o2 sensors.

Any other suggestions ?

[Cap]

The 171/174 is a System too lean in both banks..    You have said that you cleaned the MAF..  Good..  and it is Affecting Both Banks..  so it's not an Injector..  Could be a Fuel Pump starting to Fail..  If that is it, then it should get Progressively worse, till the Car is not Driveable at ALL!

IF the Codes are back..  and the Same...   then..  Check the Air Box Hoses AFTER the MAF, to see if anything is loose ( Clamps do not have to be Very Tight ).. All hoses in Place?..   one of the Symptoms of the 'Both Banks Lean' is an Air leak after the MAF, and before the Throttle Body..  Do you have an Air Filter in the Box?..  the Spyders will not run Properly if the Air Filter is Missing OR if the Air Box is not Put Together Properly..  Check the 'Box Joints' to see if it is sealed..  if not then Fix It..  that has been a Problem Before..

That is a Good Place to Start..  Well actually the First Place to start is getting the Codes..  Then Proceed from there..

Cap

[vatovey]

thanks for the tips Cap - much appreciated.

Ok - I've replaced the original o2 sensors, took car for a spin - cruised at 70mph, all good  s:) s:)  , accelerated to 75mph - CEL came on  s:( s:(

As it was dark, I've not been able to take a look at the hoses mentioned, but will do so in the next few days.

If I cannot find a problem with said hoses, would anyone local (or otherwise) be willing to loan me their untampered o2 sensors (with that person using my sensors) so I can get it all fixed under warranty ?

I don't think the warranty company would take to kindly to seeing that I've cut and re-soldered my o2 sensors, obviously upon return from the garage - your sensors would be returned (and fitted by me if needed).

Cheers, Vaughn.