code p0171 p0332 wont start now

I'm bringing this thread back. I let the car sit for 10 months. I finally took it to a mechanic who replaced the IAC valve. I re-read this thread and totally forgot that I had already replaced the IAC. I also replaced the MAF last year.

The mechanic, of course, had no issues getting the car to start or drive once they replaced the IAC. I drove it for about a week. For the most part it started up just fine, but intermittently it would need about 5 or 6 tries of cranking before she would fire up. By the way, when I got the car it had an aftermarket K&N style cone filter in plexiglass housing. I had the mechanics install the factory air intake unit.

Then one morning earlier this week I noticed a slight miss (or bucking feeling) while driving with the heater running and the SES light came on with P0101. The SES light went away but the code is still in memory. She drove fine all week until last night. I was on the freeway with my foot on the throttle just enough to keep pace when the engine felt like it was losing power. If I put my right foot down, the motor would power up and go strongly but if I just had enough pressure on the pedal to keep steady, it would keep bucking and get worse as I got home. I barely made it home. I could hardly move it 50 feet this morning to make way for my truck to get out of the driveway.

Something is still very wrong. If I replace the IAC and only put a few miles on before it gets gummed up, needing replacement again, what would cause that?

I'm still thinking it's a vacuum leak but I just can't seem to find it. Also, as I describe last night's problem, the SES light did NOT come back on. Does anyone think it could be related to a crankshaft sensor?

What about EGR? I checked and the valve is clean but the mechanic at work suggests the spring itself could be worn out.

at this point I have no idea... sorry.

Ok so I get the new EGR installed and go to erase the codes before I fire it up. First I checked the codes, and a new one popped up. P0101 (MAF) and P0121 (TPS). I cleared the codes with the new EGR in place and drove to work just fine. I'll drive it around for a while and see how it goes.

I have driven the car a handful of times since my last post. it occasionally works flawlessly, but most of the time it acts up, especially if I drive over 5 miles.

The other night the motor would cut out as I was cruising along so I had to keep my foot on the gas. At a stop sign the idle was about 1100rpm. Further down the road it started bucking really bad and making a loud rumbling popping noise out of the exhaust for the next 10 miles home. The tranny started acting funny - not slipping but not shifting at the right points and only then would it shift if I played with the throttle. Also the boost gauge was reading very high under light throttle. It only seemed to work well above 4000rpm. WTF!??

did anyone check the wiring to the MAF? just guessing at this point...
are you referring to the stock boost gauge or do you have an actual one that reads boost?

if you unplug the maf does it act any different? bad maf/maf wiring can cause the trans not shift right

to check for a vacuum leak spray carb cleaner at the vac hoses and around the TB and SC. Vac leak can cause it not shift right and the boost gauge to go up

bucking and popping noise sounds like you are misfiring. are the spark plugs wires good? but could also be a vac leak...

also check your wiring harness for the engine. i had a similar problem with my old engine, car would randomly buck and then stall for no reason but no codes....replaced the fuel pump, filter, etc, when i did the motor swap i swapped the harness too and found frayed wires where the harness goes above the radiator.

but it sounds to me like you have a vacuum leak thats getting worse.

liquifire - stock boost gauge. thanks for the tips guys, i'll have to try your suggestions saturday and report back.

for the record the stock boost gauge is inaccurate as hell and should not be replied upon for anything. although it would be possible (not sure how likely) for the stock gauge to read a difference in boost from its normal if the vac leak is severe enough i would think?...

I let the car sit for well over a month after my last trip of barely making it home. It fired right up. I let it warm up for a bit and it seemed to idle normally. I shut it down. It fired back up. I disconnected the MAF and nothing changed in the idle. However, I applied the brake and noticed a minor decrease in idle, but not low enough to stall. I kept my foot on the brake and put the tranny in Drive. No change. I put it back into Park and the idle slightly fluctuated but again, not low enough to stall. I shut it down and reconnected the MAF. It fired right back up. I did have a TPS code P0121 in memory from last time, along with the P0101 (MAF).

It is very sunny right now so another visual inspection of vacuum lines looks good. I'll go spray the lines and see if I find any changes in idle.

i just fired up the motor and used brake cleaner to spray the vacuum lines and around the SC and TB. Several times. No change in idle.

I even unplugged the MAF again. no change. I unplugged the IAC and the TPS. There was a brief spike in idle with the TPS disconnected but it continued to idle normally. After that I checked for code and got P0102 and P0122, both related to low voltage for MAF and TPS. I cleared the codes and went to pick up a pizza. Drove fine both ways. Fired up on the first crank each time. STRANGE. BTW Happy Easter.

edit: i will check for frayed wiring next.

Still haven't checked for frayed wires but will try tonight. Do my symptoms sound consistent with a bad CPS or perhaps leaking LIM gaskets or head gaskets? I'll check the fluids later for mixing oil/coolant and report back.