Another issue tuning with chrome

[Greg E]

If it's an exhaust side leak, an intake pressure test won't show that. I may need to do my shop vac trick on the exhaust side. Set the shop vac to blow and duck tape it to the exhaust pipe. That's how I found the exhaust leaks on my car...

I love you sometimes.

[DrGonzo]

LOL I couldn't for the life of me find the damn leaks on my car. So I duct taped the shop vac on blow to the exhaust pipe and bam, found the two leaks I was looking for

[CoopKill]

Just throwing this out there, are you sure the fuel pressure gauge is showing correct pressure? The first one I installed was showing 52 lbs when in reality it was only 18 lbs. That really messed with my o2 output.

[mjannusch]

Is the car a CA emissions car, or Federal (look at the emission sticker under the hood)? O2 sensor pins are swapped between the two versions. If the ECU is reading the wrong O2 sensor for the bank it is trying to tune, it'll do strange crap like that. You can try periphery 0 bit 2 set to disabled to switch to single-sensor fuel trims to see if it reacts any differently. If it does, consider switching the ECU or harness to the other mode (Fed or CA).

[DrGonzo]

Just throwing this out there, are you sure the fuel pressure gauge is showing correct pressure? The first one I installed was showing 52 lbs when in reality it was only 18 lbs. That really messed with my o2 output.

Thought of that and started bumping up the fuel pressure to see if we could get the rear to cycle at all. Took it up to 60 psi and the front bank was super rich, rear never moved. FPR is also mounted on the rear rail so if it was a pressure issue, the front would not be rich as it is the furthest from the FPR.

Is the car a CA emissions car, or Federal (look at the emission sticker under the hood)? O2 sensor pins are swapped between the two versions. If the ECU is reading the wrong O2 sensor for the bank it is trying to tune, it'll do strange crap like that. You can try periphery 0 bit 2 set to disabled to switch to single-sensor fuel trims to see if it reacts any differently. If it does, consider switching the ECU or harness to the other mode (Fed or CA).

Sensors are not swapped Front reads front and rear reads rear on evoscan. Secondaries are removed and disabled. Running on one O2 will not work in this situation as the ECU defaults to the rear bank when you switch it to single sensor.

[CoopKill]

Thought of that and started bumping up the fuel pressure to see if we could get the rear to cycle at all. Took it up to 60 psi and the front bank was super rich, rear never moved. FPR is also mounted on the rear rail so if it was a pressure issue, the front would not be rich as it is the furthest from the FPR.

Hmm, have you checked the injector wiring? Sure sounds like a/the rear injectors are not firing proper, and you have swapped them out so not the actual injectors.

[mjannusch]

Sensors are not swapped Front reads front and rear reads rear on evoscan. Secondaries are removed and disabled. Running on one O2 will not work in this situation as the ECU defaults to the rear bank when you switch it to single sensor.

Connect the "working" front sensor to the rear O2 connector and run in single sensor trim mode to test.

[DrGonzo]

Hmm, have you checked the injector wiring? Sure sounds like a/the rear injectors are not firing proper, and you have swapped them out so not the actual injectors.

Bill, You're killing me here... It's not a wiring issue.

Connect the "working" front sensor to the rear O2 connector and run in single sensor trim mode to test.

Please re-read the entire thread before commenting.

[CoopKill]

You have the original ecu? Maybe swap it in? Or swap that ecu into your car?

[DrGonzo]

We have the original ECU but I don't think we can log to Evoscan with it. I can't remember what the exact problem was we ran into trying to log to evoscan. I'll need to check with the owner to see if he remembers.