Another Catalyst Test

[ns158sl]

I can only think of this being another catalyst test? Commanded fuel stays at 14.1 yet the wideband reads uber rich for a little bit and then everything comes back to normal. I double checked with an older version of HPT and the tests that were visible are still disabled. Its super annoying because I have yet to have the Idle Airflow Adapts dialed in so it usually like a banshee and then usually die. Happens around 150 to 155 degrees F. Starts reading rich around 4:13:500. Only other thing I seen that might correlate would be Injection Timing Normal ECT?

[edcmat-l1]

I can only think of this being another catalyst test? Commanded fuel stays at 14.1 yet the wideband reads uber rich for a little bit and then everything comes back to normal. I double checked with an older version of HPT and the tests that were visible are still disabled. Its super annoying because I have yet to have the Idle Airflow Adapts dialed in so it usually like a banshee and then usually die. Happens around 150 to 155 degrees F. Starts reading rich around 4:13:500. Only other thing I seen that might correlate would be Injection Timing Normal ECT?

Without even looking at the log I'd doubt it's a catalyst test. That would show up in the commanded EQ or AF. At that temp and the fact that it's NOT in the commanded EQ, I'd be looking at evap control. If your system is still completely intact, it's probably running the evap at that time.

Just a SWAG by symptom without looking.

Edit: Looking through the log the injector PW seems to stay pretty stable, even drops some like the trims are trying to bring the O2 back down. Again leads to the fuel coming from a different source.

[ns158sl]

Yep. Just noticed it goes to FTC 6. I never would of guessed evap would pour that much fuel to it lol. Thanks again!

[edcmat-l1]

Yep. Just noticed it goes to FTC 6. I never would of guessed evap would pour that much fuel to it lol. Thanks again!

That's actually part of the EVAP monitor. When it runs the test it needs to see that "rich" shot. Needs to see the O2s go high.

[GHuggins]

Just saw this - Great catch Edcmat-l1.

FWIW just something to add to it - evap should only be vapor. If you indeed have raw gas in the system you need to replace the canister and look into possible heat shielding around the exhaust around the tank. I used to install a couple of cooling fans to blow under cars on the dyno because they would boil the fuel in the tanks where they got so hot. Actually heard a horror story from one customer where his original tuner and build shop had the pumps wired wrong and boiled the fuel from a constantly running dual pump setup and I guess he had enough pressure and heat build up in the tank cause it puked raw fuel during a purge event causing his to catch on fire.

[ns158sl]

Everything was replaced a year ago because it you couldnt fill the tank. Im not sure if reading 11.4 AFR is normal or not during an initial Purge test. Seems it is only any issue from a cold start and warming up. Again never ran into this. I probably wouldn't of caught it or cared a whole lot, but it drives my idle into oscillation from lack of adaptives being dialed in.

[blindsquirrel]

'Poor fill' issues can often end up spitting fuel over into the canister, which then ends up way rich when purge opens. Some platforms are just not good with the venting while filling even when everything is as it should be.

[edcmat-l1]

Everything was replaced a year ago because it you couldnt fill the tank. Im not sure if reading 11.4 AFR is normal or not during an initial Purge test. Seems it is only any issue from a cold start and warming up. Again never ran into this. I probably wouldn't of caught it or cared a whole lot, but it drives my idle into oscillation from lack of adaptives being dialed in.

I can't say if that rich is correct or not but the spike is correct. It does need to see a rich shot. If it doesn't it's going to assume the solenoid didn't open or there's a "gross leak/no flow" P0455. If it thinks it's too much it SHOULD set a P0496.

Depending on how you have your DTCs setup, what's turned off or not, would tell you if it's too rich or if there's another problem with the system. It needs to see that rich shot and then at some point it needs to check the vacuum on the tank and pass the no leak test. I'd start by setting anything EVAP related back to stock and see what passes and what doesn't.

Just saw this - Great catch Edcmat-l1.

Thanks Greg. I am a diagnostic guy first.