What do I Try Next?

[Phx99Cobra]

I need help. In have a 1999 Cobra and all the mods are in sig. I have recently had the car tunned and leaned out the fuel a little. A few weeks later my car started hitching and popping and not having any power around
2k rpm...Threw a code P1151... After that i changed the o2's but it didnt work, then i clean the MAF and that has seemed to stop the hitching and popping, but the car agian threw the same code...what should i try next?

[fazm]

have it retuned? sounds like the tune is just too lean to me

[Ruckus46gt]

check for vacuum leaks (exspecially after the maf), could be a bad egr valve(stuck open), bad fuel pressure, bad injector, bad fuel pressure (to high or to lean), oil dipstick not seated properly, exhaust leak, cam timing, bad computer, cylinder compression. Its hard to say really. If you know somoene with a scanner hook it up and go for a ride and watch the fuel pressure at that rpm range and computer af ratio read out. Also pull a plug see what color they are (think the code you are throwing is passanger side so check those plugs)

[93mustank]

Does the car drive without the popping and bucking now? If so put a piece of tape over the check engine light,

And is there any other codes?

[jjmatheson]

Where are the long term fuel trims and check baro it should be around 151 at 1200 ft.

[Phx99Cobra]

Dont have the lay out on the long term fuel trim... I think i will do a trial and error test to a few things this weekend and maybe it will be something easy like the egr...lets hope anyway....Thanks for the feed back, i will let you know how it goes

I also have a safe tune which has very conservative fuel curves and i still throw the code

[Phx99Cobra]

Fuel Trims were good, but the o2's were having problems, but they are brand new.

It ended up being a wire that shorted. I fixed that and it has been fine

[jjmatheson]

Awesome

[ITLRUN]

Like Fazm said, have it retuned. It sounds like you started having the problem, after you leaned it out, Mike.