Check engine light on - now what?

[rockind308]

Need some help. I have a 2008 H3 3.7L H3 with 2K miles that I had a K&N air filter system and catback exhaust system installed. Now I have the check engine light on, the engine is sputtering and on star diagnostics says the engine is running too lean. Now what should I do? Are there other adjustments I need to have done. Don't want to burn up the engine. Thanks for any help.

[HUMTECH]

Make sure there are no leaks after the mass air flow sensor to the throttle body. This will cause it to run lean as more air than the maf sees is getting in the intake. Also make sure the MAF is not contaminated with the oil from the air filter, this will cause the sensor readings to be out of whack.

[trailerpup]

How long have you had the stuff on there... you didn't specify. Did it start doing this right away. If so, it sounds like a vacuum leak. Cat-back is not the problem.

[richl]

sputtering ....... humm sounds like a misfire. which in return can set lean codes........ really i need more info please.........

[rockind308]

Drove about 150 miles after installation of K&N and catback exhaust. Drove good one day, filled up tank and went home. Next day was hard to start and would run but rough. Does that help.

[richl]

unfortunately no.......