If you are sure you have no vacuum leaks, I'd: A) (preferrably) replace the filter with a stock paper, or B) (relunctantly) clean the K&N and not use as much oil.

Then I'd clean the MAF sensor again and see what happens.

 

I am not sure if I have vaccum leaks? how can I be sure? tighten the clamps?

 

I'd check to make sure they aren't loose, but don't overtighten them. Check all the fittings that hook up to the intake as well.

 

So after I cleaned the MAF sensor and replaced the air filter putting a paper filter and cleaning the air filter box the car ran fine for the next 2 weeks. Yesterday, the battery was dead b/c of the rear cam that I installed (forgot the power on), so I jumped started it worked fine. Today, the same check engine light (code P0171) came back - yes I do have a scanner now!

I'm gonna go ahead and give it another cleanup this weekend but I really think everything is clean.

Also, I have to note that I did smell a few days ago a strong gasoline smell from the exhaust (but not like rotten eggs so not the catalytic converter)

please advise, thanks

 

I also noticed some rough idling and this happened (again) right after I put gas in it. Should I clean the fuel injectors?

btw am I the only one here that puts 87 gas in it? the manual says its ok

 

I run 87 all day long... I would start looking into what other possible scenarios it could be...
Doubtful its the spark plugs, but you never know. They are CHEAP so replacing them with stock from gene at gmparts house might be a start... Run with the vacuum leak idea, but that isn't gonna be that easy to determine. You could also try the sea foam approach... Keep me posted George, DON'T GIVE UP!

 

The spark plugs are new , I was thinking that WHILE installing them the mechanic misplaced some hoses (as I read that in this forum that this is common).

Plan of action:

1- clean the MAF again
2- Make sure the air filter is installed the right way
3- check that all the clamps are tight and no hoses are bad
4- inject the sea foam in the car

and we'll take it from there.

PS: mechanic suspected that my fuel tank might need to be replaced - I don't agree with him

 

Is checking for a vacuum leak that hard? Should I ask the mechanic to do it?

 

With the engine running and hood up you can sometimes hear a leak (hiss or whistle) but it can still be hard to locate where it is coming from..

You can get a can of carb or TB cleaner, lightly spray a dab where the accordion hose couplers clamp onto the air filter box outlet, resonator (both sides) and TB, by the MAF where it seals. If your idle changes when you spray, you found a leak. If so, investigate closer.

You can also spray some cleaner at the primary/closed PVC hose which runs from on top of back of the motor (cylinder head cover) in an elbow with a short hose going into the black plastic intake manifold (the big plastic thing to the right of the TB).

Make sure the secondary crankcase vent hose (under the rear of the plastic resonator) is properly on both the valve cover port and resonator nipple. That secondary hose can get hot over time and get loose, if it is it would be a cheap fix with a piece of 1/2" emission hose.

Filter wise:
If you have an 06/07, make sure the canister air filter clamp is properly in place and snug. If you have an 08+, just make sure the panel filter is properly in place so when the box lid is on, you get a seal at the outside sealing edges of the filter.

 

Thanks a lot guys 2 questions

1- What is the best way to use Sea Foam? put the whole bottle instead of fuel when my gas tank is almost empty then fill it all the way up? what do u recommend?

2- Is there a chance setting my car on fire while doing this vaccum leak testing with TB cleaner since its highly flammable?

thanks again