I have an 02 WRX with full decat and SS Ecutek remap. Since refitting the ECU the car has become progressively more hesitant during acceleration. I’m convinced that this has nothing to do with the remap as it is a standard SS postal map which has caused no problems in other MY01+ cars. More likely the remap/ECU reset is highlighting an existing problem that didn’t show up on the standard ECU.

Anyway, once over it’s initial lurch(going from closed loop to open loop?)the car pulls well on WOT, with little if any hesitation. The problem seems to occur under partial throttle accel. The CEL came on a couple of times (flashed for a while before going out. Eventually staying on.)The select monitor shows that the ECU has logged ‘misfires’ on cylinders 1 and 3.

My initial thought was that the spark plugs were u/s or req regapping, but on talking to Pete at SS he suspects that as the problem is getting worse it could also be the front o2 sensor.

Before taking the car to my local dealer who knows even less than me. (it was the 1st time he’d used the select monitor!) I want to be armed with as much info as I can.

Has anyone had any experience with this problem or know of any other potential areas to check etc. I’d be most grateful. I don’t want the dealer costing me a fortune replacing parts unnecessarily or bulls!tting me(I believe 01+ lambda sensors cost a few bob!)

For info: Idle seems ok, fuel consumption is normal, boost is stable at 18psi.

If there’s any info I’ve missed please ask

Cheers

 

Taylor...I'd say it's possible that the 02 sensor is reading incorrectly. I had it on my MY02...it was found (eventually) after checking the error codes many times - but they didn't tell me which code confirmed the problem. If you've got an induction kit fitted, the problem will be worsk, as with mine. Sensor was replaced under warranty.

Get it checked asap, as it wasn't doing the engine much good - lean running on two cylinders.

 

Absolute Shower

When your lambda was going did it give the same symptoms as I described above?

PS. No induction kit. Just a panel filter

[Edited by taylor - 6/27/2003 11:51:13 AM]

 

At times yes, but not to the same degree as yours. Mine wouldn't run as sweet and the ECU light was on/off...It was reset a few times by the dealer before they found the correct fault code. The codes are the key - and a decent dealer to read them.

 

Taylor

Had the same on my car (on the standard ecu) and the new front lambda sensor cured it. It was awful to drive until fixed.

 

Hey Pete...it's Anthony (Mr SR40)...

It was my front sensor too...could it be that they work harder than the rear O2?

 

Hi Pete

I'm not doubting your original diagnosis, just trying to increase my knowledge on the subject. I hate it when dealers try and bamboozle me with technical stuff just before whacking you with a huge bill. I like to be able to at least ask the right questions, give them the impression I know what I'm talking about. That way they're less likely to take the pi$$.

Thanks for your help so far. It'll be a couple of weeks before I can get to the dealer(I work offshore). I'll let you know how I get on.

 

Hi Taylor

The problem is the diagnostics in the manual. The front O2 is barely mentioned for this fault, although it runs to a very long list of possibles. As with Ant, myself and another that I know of (standard car) the front O2 was at fault.

 

Hi Ant

They do work hard as they sit in a gas stream that is close to 1000degC, but this is what makes them so accurate. They should be up to it but because of the conditions that they work in, some failures are inevitable.

They aren't cheap!!

 

Well I've been to the dealer and I'm still none the wiser, he reckons it may be a faulty nuetral switch. Anyone heard of this problem? After he reset the ECU I took him out for a spin to show him the problem, of course, the damned thing worked fine.

Needless to say the light is now back on and the lumpiness has returned. I'm beginning to wonder if it's the CEL thats making me paranoid and causing me to imagine half of it!

 

I have the same issue, I have CEL codes for mis-fire on cyl 1,2,3 coming up soon after fitting a full APS CS kit. I was assuming that the problem was caused by the piggy-back computer having a dodgy connection, as the first time it showed was with a passenger, who obviously had their feet 'on top' of the ECU.
The car does not seem too 'lumpy' to drive, but with the number of changes that took place I don't know what 'normal' should be like!
Does anyone know the part number and price of the front O2 sensor? If it is reasonable I may get one ready!