I got another cel which said system too lean bank one. Few days ago o2 sensor, maf sensor was replaced, also replaced all 4 coil packs with ngk plugs. Still have the problem what could it be?

 

clogged fuel injectors or filter?

 

Well a lean condition is caused by a vaccum leak........90% of the time. Now would be a good time to change all your vaccum check valves and vaccum lines.

 

i did have no leak its at like 20-25 at idle

 

i replaced the plugs my self, there is a plastic on the middle of the plugs, was i spossed to take them off or let them stay there because some one was telling me that it might cause my plugs to not function right which could cause misfire. does it make sense

 

A vaccum reading from your boost gauge is not a diagnostic tool, a vaccum leak can be so small you wouldn't notice it on your gauge. Your O2 sensor would notice the extra air though.

 

The check valve on top/rear of the airbox is well known to rott on the bottom. Worth a look:


This is what the valve looked like when turned over:


I had random lean code that showed up every now and then until I replaced this check valve.

 

My check valve rotted out too and I replaced it but I still had the engine code so now I'm replacing all of my vac lines. Its a pretty tedious process.

 

yea its tough guys i replaced all the vac lines and o2 sensor including the MAF, i will take a look at the check valve thank you guys

 

I checked the check valve that was ok. But when i tried to start the car it would start and stop just about the same time. So i tried again and gave it little gas then it started and ran fine. It does it everytime in the morning but after driving it its fine and starts fine too. Any guesses