check engine light, code 1222, just need to get pointed to right direction

[xcore]

background: my 95 m3 with obdi with freshy recondition engine, from headgasket up everything is new(not sure about the spark plugs tho). heavily modded engine. The car has been sitting most of the time and only being take out for a spin once every one or two weeks since early april.

today i took the car out for a spin as usual, the cel came on and it goes on and off,i thought it will goes away once i drove it longer since this car always gave all kinda of problems once i just let her sit. i did a longer drive, did a 8 miles hwy drive, stopped for dinner and a another 8 miles hwy drive home, it didnt go away. extra symptoms are rough idle at the first start after the car has been sitting, it did it at cold start( at my garage when i first start for the drive) and warm start(at the restaurant parking lot when i was heading home), but only at the first start of the car, other time is fine. one more was the car choke/hesitate when acceleration , only when i was accelerating from a light at 2nd gear right after the needle went pass 2k rpm, i shifted it to 3rd n it is fine. this only happened 3 time over the entire drive.... so any idea what could be the problem? i did used the search, but it came out with all kind of problems. sorry for the kInDa long reading:alright and please don't tell me to find a shop to do it, id do that at the end if i couldnt figure it out myself.

Code 1222
Lambda Control #1
dme detected excessive deviation in air-n-fuel mixture (too rich/too lean) longer than 10 sec.
thx guys~any input would be appreciated :redspot

[RRSperry]

Change the O2 sensor... and check for a vacuum leak.

[xcore]

Change the O2 sensor... and check for a vacuum leak.

ok, i cleaned the maf with the caf cleaner n the hesitation is gone so as the idle. but the cel is still there,again on n off while im driving it. couple more things i wanna add, the engine is heavily mod, it got custom grind cam, injector, CAI, header, trackpipe, exhaust, active chip tuned for the intake+exhaust. the cel shown after the bat is drainned and all the data in the ecu is gone. today i started up the car after sat for a one day, the idle bound up all a lil for about 5 sec then it idles fine but from the exhaust smell i can tell the car is running very rich.

[shaeff]

As Rich said, check for vacuum leaks, and if you find none, replace the o2 sensor.

Use carb cleaner and spray around any area that has air flowing through it. If your idle increases as you spray somewhere, you've found a vacuum leak. Don't forget to spray around the injector grommets and all the air pipe connections under the manifold.

[Stephen Max]

Keep in mind an exhaust leak might also be to blame. If fresh air can get at the O2 sensor then the sensor will detect it, and the ecu will think the engine is running lean and compensate by adding more fuel, without effect of course, except that the engine runs very rich. Eventually it tries to add so much fuel that it triggers the code. Look for an exhaust leak at the exhaust manifold flanges and at the header to midpipe connections.


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