I'm getting 3 different dtc's 1st is P02195 that ive read in a post that means my Evo is using the rear 02 to provide trim control instead of the front 02 but I'm also getting a P0140 bc my rear 02 has been removed, And also a P0171 too lean dtc. My car has a poor idle almost loopy idle and it's stalled a few times and seems to also get choppy when I downshift as well as backfire or pop sometimes when I shift. Because I don't have a rear 02 Does that mean my Evo is not getting any trim control? Any help would be appreciated.
My mods are:
Invidia Turboback
Walbro 255lph
DW 800cc Injectors
Home made intake

 

I'm not sure about the other codes, but P0171 I got when I used a crappy intake from ebay. I had to put the MAF back into the stock housing to get rid of the code. I made a custom intake as well but I used to stock intake arm.

 

Yeah that's the same thing i did with the stock arm with a cone filter, but it shouldn't matter bc I'm tuned with it. Anybody any ideas whats wrong with my car?

 

If you are getting p0171 you need to rescale your MAF for your aftermarket intake. (or, if you want to do it the improper way you can rescale your injectors).

This is probably telling you the same thing as P02195 - that your fuel trims are maxed and the car is still running lean.

P0140 can be fixed by re-installing your rear O2, disabling it, or putting in a resistor box (least desirable).

 

Thanks everyone for your help this site can really be helpful at times, I'm going to run this by my tuner I would have thought that EFI logics would have done that but guess not :/ is that why my STFT is at 25% at idle but quickly returns to 0 when I start driving?

 

There are quite a few things that could cause this. It is also possible they tuned the injectors for cruise and didn't scale the MAF at all (though these are semi-proportional).

You probably have a full positive LTFT low, but a correct LTFT mid.... or your mid has not had enough drive time to adjust itself yet.

 

Thanks frost although you lost me a little Im thankful for your help. Ps. I find it entertaining that you own every turbo Mitsubishi that jas ever hit our shores.

 

yeah sounds like you just need a good tune..

 

The 3000GT VR4 isn't in there... it came with a spun bearing though so it only lasted 2 days... never got a chance to own a GVR4. Almost, but not yet

If you check out the tuning guide in this section or the CT9A section it may give you a better understanding of what is going on with the LTFT.

 

It was one part bad tune and 1 part missing o-ring

I got tuned and the same day my CMC **** the bed and I brought it to to be fixed and when I got it back it was running like I said above, well forgot to put in or dropped an O-ring that was causing more air to flow in then the MAF was reading and thus causing my STFT's to rise and everythimg else that was messing up...

The thing is I took it to Sean @ Ivey Tune and he figured it out in 5 minutes...
The other shop just through more fuel at it hopping that would fix it.