vbb

Posted in the UTH section, but frankly, you guys here are more helpful most of the time. I threw a code I've never seen before today. p1129

I got in the S the other day and I noticed the slightest bit of hesitation while accelerating in 2nd gear. Didn't think much of it. Today though, before the little drive I went on, I checked my CELs with my OBDII scanner, and I got a p1129 and p1129p code. I cleared it out and went on the drive. About 10mi in to the drive I noticed a slight hesitation in 1st gear taking off from a stop one time. It wouldn't accelerate for about a second or two, and then it caught on. I finished up the drive, got some fresh gas, and headed home. When I was almost home, it did it again, but this time as I tried to accelerate in 3rd gear it had no pick up at all for a good 5-10 seconds. I had to pull over to the side, shut the car off and then back on again. It drove fine the mile back to my house, where I promptly parked it in the garage. The p1129 code came back after I restarted the car that last time.

For what it's worth, I changed all my fluids recently, and the only engine mods I have are a short ram intake and private label header (stock cat and exhaust).

Ultimately if I can't fix this on my own, I will certainly take it up to Cory. He's not exactly 'round the corner though, so I'd love to fix the car in the comfort of my own garage if possible.

9k_on_occasion

"P1129 MAP Higher Than Expected"

P1129 was my old friend back when I had a Hyundai Accent. I ended up hosing down the MAF sensor with electrical contact cleaner to get the dirt and junk out of it.

C Ory

P1129 MAP Sensor Value Higher Than Expected
Possible Causes

* Check for a vacuum leak in the brake booster or its related hose
* Check for a vacuum leak in the PCV system or its related valve
* Check for a vacuum leak somewhere in the throttle body area
* MAP sensor connector is damaged (check pins for damage, and for moisture)
* MAP sensor has failed
* Reset the PCM and perform the "idle relearn" procedure

vbb

I will check those things, and try to clean it off if it appears dirty. The idle relearn procedure is new to me though, I don't know what that is.

Assuming none of that works, and assuming I can't pick up a MAP sensor off of a part-out somewhere, can you give me an idea of how much you could get a new one for?

C Ory

I may have a spare map sensor at the shop. You can also try the "map whack"

vbb

Thanks man. I actually just got back from my garage, checked all hoses. No leaks to be found. Took my MAP sensor completely off the car to make sure it was clean, reconnected everything, and now I'm going to wait for a bit. I guess I can do the idle relearn procedure if none of this works. If THAT doesn't work, I may take you up on your offer to buy that MAP sensor off of you.

Thanks.

TepEvan

You may also try pulling the backup fuse to reset the ecu after that, but it might be 30-60 miles before the problem shows up again.