mac sk

Hi i have 2004 gt , x pipe, borla cat back, with MIL eliminators on the o2 sensors that are located after the catalyc converter, that used to be there.
Everything was cool until yesterday, when i have engine code

Sensor 2 bank 1 stuck lean.

Now the car uses lots of gas. I dont understand, i would think that sensors readings are eliminated using the MIL eliminators, that is why they are there.

I would appreciate anybody's help.

Thank you

WhiteFoxGT

You must mean bank2 sensor 1. The rear 02s do not read a/f. Post the exact code #

mac sk

I did not get the exact code, i just got the message on the reader,
and was sensor 2 bank 1 stuck lean.
I have to go to rescan it again to get the actual code.
The guy said it was pasenger side after the cat. converter.

??

WhiteFoxGT

yes, but the after cat 02 does not read air/fuel mixture...so you must have mis-read the scanner

cliffyk

I suspect it was code P1151, Lack of HO2S-21 Switch, Sensor Indicates Lean.

Sensor HO2S-21 is bank 2 sensor 1 (front)--which would cause the engine to run rich as the O² sensor is telling the engine the mix is lean. The PCM will make the mix richer until it has added more than 25% additional fuel, at which point it will throw the DTC...

WhiteFoxGT

exactly, the car most likely has an exhaust/vacuum leak. But we will never know until the threadstarter can figure out and interpret what hes looking at correctly

supersnake67

I had a P0420 code for Bank 1 sensor 2 stuck lean so it's not impossible. Turned out to be a faulty MIL. Used cliffyk's homemade MIL's and has been perfect ever since.

mac sk

i just got back with the printout from the store.
c
ode P2270 heated oxygen sensor (bank 1 sensor 2) stuck lean

mac sk

Code p 2270

supersnake67

Excuse my ignorance my code was a P2270 Bank 1 sensor 2 signal stuck lean not a P0420. Grabed the first code I found in my old post.