code 25, ecu/fuel pump??? Options

[6gcnoob]

i am running a GT with a 5sfe. cant pass emissions because of high NOx, and i am running a code 25( air/fuel lean). i checked and cleaned my EGR, checked the resistance on my injectors, put the stock manifold & air box on, cleaned the fuel pump filter, but still have it.

while i was cleaning it i remember one of my friends gave me it as seeing mine was garbage when i got it, he said it came out of a celica, but i think it was an ST. would that make the diffrence?

also my motor was blown when the car was bought too, but it had a 3sfe in it. i dont know if the ECU was swapped out too, havent made the effort to look yet. if it is the one for a 3sfe could that also do it too?

[alltracman78]

If you have a code 25 you probably want to start by replacing your O2 sensor.....

Is it a 2 stage idle test or is it on a dyno?

Can you post up the rest of the results?

[6gcnoob]

i did replace the o2, but with a used one that had no problems that i knew of.

i cant post my actual results, lack of a scanner

HC- limit=136 PPM me=34
CO%- limit=.73 me=.02
NOx- limit=1591 me=2218

[dgbldr]

Anything restricting fuel will make it lean, although the ECM should be able to compensate some, if you have the right ECM.

So check for correct ECM first, then look at things like restricted (clogged) fuel filter, clogged injectors, etc. Run a can of injector cleaner through or have them cleaned.

Also check that all wiring and hoses were done correctly when swapping from 3s to 5s.