[Dennis 2ss]

Hello guys i've had issues where the car runs extreme negative LTFT at -20 to -35 on both banks and the car runs pretty rough on idle and i get constant small pops and crackles everytime i let off the gas. No codes whats so ever and car still answers good when i actually floor it with no missfires or anything. Changed O2 sensors and high pressure sensor but that did nothing. Do i have a bad HPFP?

Big thanks for any advise

[18.2SS.1LE]

Have the fuel trims always been negative since it was tuned? Any changes since the tune? Pull the MAF and clean it.

[Dennis 2ss]

Originally Posted by 18.2SS.1LE

Have the fuel trims always been negative since it was tuned? Any changes since the tune? Pull the MAF and clean it.

No the trims were pretty perfect after the tune but now they’re way out of whack. I’ll try with that thanks.

[ctrlz]

Originally Posted by Dennis 2ss

the car runs extreme negative LTFT at -20 to -35 on both banks and the car runs pretty rough on idle and i get constant small pops and crackles everytime i let off the gas.

Leaky injectors or dirt keeping them from closing completely?
Does your exhaust smell like gas? Sounds like you are dumping fuel into the exhaust.

[Dennis 2ss]

Originally Posted by ctrlz

Leaky injectors or dirt keeping them from closing completely?
Does your exhaust smell like gas? Sounds like you are dumping fuel into the exhaust.

definitely does smell alot of gas. Maybe dirt? Injectors has been driven about 2000 miles and we followed all procedures that came with them from FIC. And it seems all injectors are off. Isn't that odd? Pressure set at around 2150 psi and car doesn't stumble or anything when going above 3k rpms. I'm very much a beginner at this. My tuner says he still has the rear 02 sensors on and he was following advise from Ted at Janetty that they shouldn't be turned of. Definitely not trying to point any fingers as i know Ted is great at this but maybe there was a misunderstanding with my tuner and i being Swedish lol

[ctrlz]

Your front O2 sensor is the one used to adjust the air/fuel mixture. We know that is working because your car is setting the fuel trims to reduce fuel. For some reason it is not able to reduce the flow from the injectors, even by going to extreme negative fuel trims.

Are these the stock injectors?

The back O2 sensor is used to verify the catalytic converters are doing their job. The reading from back O2 sensors does not affect the air/fuel mixture.

I am not sure of everything you have done to modify your car. You may also need to upgrade to a wide band O2 sensor. But it sounds like your current setup is trying to correct the problem, but too much fuel is getting through.

[Dennis 2ss]

Originally Posted by ctrlz

Your front O2 sensor is the one used to adjust the air/fuel mixture. We know that is working because your car is setting the fuel trims to reduce fuel. For some reason it is not able to reduce the flow from the injectors, even by going to extreme negative fuel trims.

Are these the stock injectors?

The back O2 sensor is used to verify the catalytic converters are doing their job. The reading from back O2 sensors does not affect the air/fuel mixture.

I am not sure of everything you have done to modify your car. You may also need to upgrade to a wide band O2 sensor. But it sounds like your current setup is trying to correct the problem, but too much fuel is getting through.

That’s what I thought they only were for too. These injectors are 30% over LT4. The problem only comes on idle and mild driving. Weird.

[18.2SS.1LE]

Make sure you don't have any burnt plug wires, could be misfiring showing a rich condition and the car is trying to pull fuel out.

[Dennis 2ss]

Originally Posted by 18.2SS.1LE

Make sure you don't have any burnt plug wires, could be misfiring showing a rich condition and the car is trying to pull fuel out.

no missfires what i can see on the logs. Car just runs super rich

[18.2SS.1LE]

Originally Posted by Dennis 2ss

no missfires what i can see on the logs. Car just runs super rich

Still worth checking, might not show up on a log since it's probably intermittent. You say you can feel it misfiring but no codes have popped up.

[ctrlz]

Originally Posted by Dennis 2ss

The problem only comes on idle and mild driving. Weird.

You need to drive with a scan tool and see what the trims are doing.
Compare closed loop to open loop modes.
In open loop the fuel injectors go by the map loaded with your tune.

[Katech_Mike]

Have you checked the oil?

[ctrlz]

Originally Posted by Katech_Mike

Have you checked the oil?

Good idea.
see if level is high and it smells like gas.

[Dennis 2ss]

Originally Posted by Katech_Mike

Have you checked the oil?

definitely has oil dilution. 100% smells like gas.