STFT misatch

[rodks03cobra]

I have been fighting a fuel trim issue. My upstream Bank 2 sensor wants to peg at1.25 at idle while my bank 1 is at .90. I data logged my O2 sensors with the key on and got .5V on Bank 1 and 0 on bank 2. I have voltage with the car running. I have done a smoke test and no intake leak, cleaned my MAF and air filter. What is odd is no trouble codes....any ideas?

 

[DSG2003Mach1]

To me it’s odd you have no voltage engine off on that bank. Kind of a pain in the ass but my first thought would be to swap sensors bank to bank and see if it follows

 

[03cobra#2]

Fought the same issue last week mine ended up being a bad injector plug. Of course it was #4 so the blower had to come off to get to it.

 

[rodks03cobra]

That's a bigger job then you want to....

 

[rodks03cobra]

To me it’s odd you have no voltage engine off on that bank. Kind of a pain in the ass but my first thought would be to swap sensors bank to bank and see if it follows

I agree with you and already tried the sensor swap.... thinking wiring issue or maybe ecu...what puzzling me is no codes

 

[rodks03cobra]

datalog if anyone has any ideas

 

[rodks03cobra]

Anyone?

 

[DSG2003Mach1]

@decipha

 

[Crimson2v]

Can you drive bank two lean and make the 02 sensor respond? What’s the rear 02 reading on both banks when warmed up?

 

[rodks03cobra]

I have a custom tune by Lund and he doesn't tune Cobras anymore. I also have my rear cats turned off

 

[decipha]

The only way to properly diagnose an 03/04 cobra is with a moates quarterhorse and tunerpo.

See if you can find one and if so you can very easily see whats going on just by watching the dashboard.

 

[rodks03cobra]

Have a shop close by that I am taking to tomorrow..I will update when I get a diagnosis

 

[rodks03cobra]

Problem fixed open wire on #1 coil pack signal wire.. actually the AET test wire was cut