occasional po174, but no check engine light
 

I have a scan gauge in my truck and can read codes on the fly as I am driving. My truck keeps throwing am occasional lean code on bank 2. I had the intake off to replace the cht and knock sensors. I also had to repair the motion charge door harness. I have put around 100 miles on the truck since I put it all back together. I have checked the vacuum lines and haven't found any vacuum leaks. I had one issue when replacing the sensors. I didn't drain enough coolant and had some coolant go into the left cylinders. I pulled the plugs and got out as much coolant as possible and then installed new plugs. I used a shop vac and spun the motor by hand to clear the cylinders of any water. the truck runs like it use to except the occasional code, but doesn't trip the engine light. Could the coolant have caused the 02 sensor to go bad? What's the best way to check for intake leaks? My mods include afe intake, bbk throttle body, super chip flash paq, magnaflow hi flow cats with a 3 in exhaust and magnaflow muffler.

It's the combination of the AFE and the tune. It has to be custom tuned for that intake.

it has ran cherry for the past 5 years with the mods and no codes. the codes have only come up after the coolant issue and pulling the intake manifold to replace the other sensors. there is no check engine light, I have to do a manual scan on my gauge to read current codes. but the code is intermittent, which is why I assume there isn't a check engine light.

Well my truck stopped throwing its code. discovered it started running overly rich and couldn't out run my buddy's 4.6. i realized if i take the cover off the afe box the truck runs perfect. It now pulls hard through out the rpm range without any bogging or hesitation and idles smoothly. Now I'm wondering... Will a switch from 3.55 gears to 4.10 gears help my take off enough to justify the cost?

What are the specs of your truck? And if you don't have a custom tune, get one. My 4.2 with k&n intake and vmptuning custom tune has beaten 5.4s and 5.3 chevys and also a 6.0 Sierra Denali. Never raced a new ram or tundra yet but I honestly don't think I'd beat them anyways. Trying to get my buddy that has an 06 cobalt ss to race me but we need a good place to do it so we don't get caught. He has the N/A 2.4L one. My scangauge has read 203hp with my mods in 6000+ ft above sea level. My friend, s cobalt is supposed to be 171hp at sea level. I'm thinking it will be close.

Afe, intake, bbk throttle body, hi flow cats, 3in exhaust with a magnaflow dumped and a flashpaq. My buddies 4.6 is still pulling me on a run

I mean like is yours a 5.4? And what year and rear end and cab and bed configuration? And what about your buddy's truck? You said 4.6 on his...but what else?

My truck is an 04 supercab 5.4 with 3.55 gears and 40000 miles. His is an 08 supercab 4.6 with 3.55 gears and miles 85000

Oh ok yeah that sounds a little wierd. I would get a custom tune for that tho. It could just be running lean which could be sacrificing power.

His other thread says it's running rich, not lean.