lean bank 1 and 2.......

[jaredssc17]

i have a lean bank one and bank two code come on. i just got the truck. had to pull the trans to redo it. put headers, cold air kit, t body spacer, and cat back. can this make it happen? also have a small leak off the driver side header i think. tryed carb cleaner on some intake and vac joints with no diff.in idle. maybe a vac leak? when i pulled the o2's to put in the new y pipe they didnt look white, the spark plugs looked good to. seems to have a stumbling idle also. i have no idea what to do. i dont want to start part swaping to fix it. any help would be nice.

 

[footee]

Was it lean before you put the bolt ons, um, on?

 

[jaredssc17]

i dont know i had codes from the trans. and i didnt drive the truck when i got it cuz the trans was bad.

 

[footee]

To my knowledge, the "lean bank" codes are referring to the number one and two cylinders and should have nothing to do with the tranny. I say, that with the bolt ons you have installed, the computer can't keep up with the air flow, causing it to run lean, or think so at least. I say get a programmer for it or a chip at least. What motor are you working on by the way?

 

[jaredssc17]

its a 4.0

 

[footee]

Like I said, I've heard that when you strap on a CAI and freer flowing exhaust, it can cause lean conditions in the motor. I hear that alot on F-150s, may be the same thing.

 

[MAKG]

To my knowledge, the "lean bank" codes are referring to the number one and two cylinders and should have nothing to do with the tranny. I say, that with the bolt ons you have installed, the computer can't keep up with the air flow, causing it to run lean, or think so at least. I say get a programmer for it or a chip at least. What motor are you working on by the way?

Don't make s**t up.

You are simply not going to get anywhere near maxing out the injectors with such simple and modest modifications. That is not the problem.

And you don't have 6 HEGO sensors. There are only two. They don't know which specific cylinders (if any) are coughing up excessive oxygen.

Lean codes mean that both upstream oxygen sensors measured under 0.5V when the computer commanded the engine lean. ANYTHING that can do that can flip the codes. There are quite a number of possibilities.

You need the assistance of someone with more experience. This is IMO the second most difficult diagnosis you can do on the truck. The first is an intermittent no-start.

 

[jaredssc17]

well i had it fixed, well i thought i did. i toke the iac off, it was all gumed up. cleaned it and ran some sea foam in the tank and vac line from the power booster. it helped with the ruff idle. then i cleared the ck eng codes. then they came back, so i changed the iac. didnt help. then i started to hunt for the leak(s) off my headers. found two bolts not tighting down. so i was pulling the bolts back out and dont ask how but broke the egr. it was badly rotted out any ways. so i pulled to egr tube off and got a new egr, fixed the leaks on the header. reset the ck eng codes. ok test drive time. no ck eng light. sweet!! next day start the truck up and started driveing for a little while and bam! ck eng light. theres 100 bucks gone. well im going to go back to banging my head on a wall for now. ne thoughts on lower intake gasket??????

 

[MAKG]

As I said, you need professional help.

You likely wouldn't have spent $100 on competent diagnosis.

 

[jaredssc17]

well MAKG i hope your talking about my truck. changing thos parts that i just did it needed any ways. but this is my dd. so down time i cant have. need it 6 days a week.

 

[wa2be]

well i had it fixed, well i thought i did. i toke the iac off, it was all gumed up. cleaned it and ran some sea foam in the tank and vac line from the power booster. it helped with the ruff idle. then i cleared the ck eng codes. then they came back, so i changed the iac. didnt help. then i started to hunt for the leak(s) off my headers. found two bolts not tighting down. so i was pulling the bolts back out and dont ask how but broke the egr. it was badly rotted out any ways. so i pulled to egr tube off and got a new egr, fixed the leaks on the header. reset the ck eng codes. ok test drive time. no ck eng light. sweet!! next day start the truck up and started driveing for a little while and bam! ck eng light. theres 100 bucks gone. well im going to go back to banging my head on a wall for now. ne thoughts on lower intake gasket??????

I had the same codes and went through a few rounds of repairs before finally replacing the upper and lower intake manifold gaskets. This took care of the problem for me. Spent about $75 on the gaskets (I did the valve cover gaskets too while I had everything apart). Took about 10 hours total to do the entire job. It's not hard, just very time consuming because you have to pull a lot of stuff off to get access. I also spent a lot of time labeling everything to make sure it went back together correctly.

 

[BrokeRecord]

My 99 ~4.0 had mostly left bank sometimes right bank every winter, on inital start up. Early 4.0 computers were too pickey about backfires and misses. I was losing my prime overnight because of leakage. Then I'd turn the key on start before the fuel pump re-primed the fuel. My 07 works perfect, except for that silly Tire Pressure Light