I have a weird glitch that I couldnt pinpoint so far. This is what it does at its worst


thats while stationery not touching anything at all apart from those two revs where I blipped the throttle. This happens completely randomly. For example until it started happening today I drove about 10-20kms without any issues or hiccups. But once it does it only gets worse and it does it even while under acceleration - jumps and jerks the car a bit. It feels like suddently for half a second lifting your throttle completely. And when this happens car is running rich (dont have AFR yet but I can definitely smell lots of fuel burned as soon as it starts when stationery). It has been happening randomly for a few days. Diagnostics havent revealed anything and that CEL is on because of a O2 lambda sensor - but that has been runing fine for a few months.

What Ive tried so far:

- replacing the fuel pump relay (+ mixed all of the others inbetween since I couldnt get more than one this week)
- replaced MAF sensor
- all the common hoses are securely connected and there doesnt seem to be a boost leak
- charged the battery overnight

What Im thinking of checking:
- Spark plugs
- Connecting it to diagnostics and looking at throttle position when it does start happening again (with help of a friend)
- cleaning the TB

Any other ideas? Yesterday I tried looking for a similar problem like mine here via search but to no avail.

It only starts to happen after the oil temp raised above 70°c from what I could gather today.

Today I tested a new battery. Everything went away and seems to be back to normal, even when I swapped my old one back - Im baffled.

Curious.

I've had an unstable idle ever since I tuned mine. Tuner had me replace primary 02, sparks, leakdown, comp test. All was good except money in my pocket. Still having it, though not as bad as you say. Maybe when you changed the bat stuff inside ecu reset? Are you tuned?

Yup Im tuned and I was for past 1 - 1.5 year. There werent any issues whatsoever.

Changing the battery probably unveiled a dead O2 sensor (front) so a replacement is on its way - that might actually make sense in all of this chaos. P2253 code popped up - got it scanned today.

Nope, neither. I only have a KN drop-in filter.

I have changed the front O2 sensor for a NGK one. Didnt help. Now Im trying to hunt down either electrical failure or an exhaust leak - we will see what comes out of this.

I had a non-Evo that did that when the coolant level dropped too low, i.e. leaked.

I actually replaced my MAF for a known good.


Since the car popped that front o2 sensor code everything went back to "normal". But Im just throwing parts at the problem and we will see what comes out of it. Next week (hopefully) I will be making sure there is no leak around front O2 sensor (in front or behind) I ordered all the required parts from mitsu (screws and gaskets). And Im gonna try to install a sparkplug non-fouler for the rear one - may be ECU got fed up with that code

I will keep you guys updated on how its going and what resolved it - if anything will. Im hoping ill help someone with this issue in the future.

To put closure on this. I finally got rid of that front O2 bank code. All that had to be done is to bring it to a better mechanic after changing to NGK O2 sensor. He erased completely maps, memory and all that was learn throught the use of OEM O2 sensor in the ECU and let it relearn it - everything is now working as it should.

But other than that I resealed my muffler completely from the engine to the back. The non-fouler hasnt helped me with the rear code - I have to disable that code with a tuner.


Good luck to anyone with this problem!