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      05-18-2022, 08:44 PM   #1
fstm5
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Rpms surging on idle and cold start

So, never thought I'd be making this post cause I've always read about it but didn't think it would happen to me but here we are now :



Around two ish weeks ago I decided to take out my MAF's and give them a clean with a MAF cleaner, took them out unplugged it, held it over a towel gave it a nice spray and let it dry for 20-30ish minutes, once it was dry I put it back in plugged it back up and continued on

Ever since then my car has been running very odd, no misfires or limp mode but on idle sometimes it feels like it's about to stall out or the rpm just surges a bit and this is exaggerated on cold starts, I assumed it's possibly the computer getting used to a cleaner MAF or since I had unplugged it it might have reset, I didn't really think much of it until yesterday where I got a check engine and the code was as follows 118111: Mixture control 2, across banks: Mixture too rich

From my knowledge this could be anything from MAF to all the way to injectors but I'm assuming I messed my maf sensor up for this to happen I don't think it's an injector

I cleared the code then proceeded to drive and it hasn't come back on ever since, but I'm curious if anyone else has experienced this, my car is still running a bit odd on idle especially at cold starts
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      05-19-2022, 03:31 AM   #2
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Try another clean with the spray closer up.
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      05-20-2022, 07:46 PM   #3
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Quote:
Originally Posted by M5Rick View Post
Try another clean with the spray closer up.
Did that but for some reason it's still pretty rough on idle on cold starts, assuming it's leaking injectors which I know there's an extended warranty for them
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      05-21-2022, 01:46 AM   #4
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Quote:
Originally Posted by fstm5 View Post
Did that but for some reason it's still pretty rough on idle on cold starts, assuming it's leaking injectors which I know there's an extended warranty for them
Take it to nearest dealer and have injectors tested if you think it may be that, if it is an injector then they'll replace the faulty one only but if the motor is tuned then warranty is void.
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      05-21-2022, 02:27 AM   #5
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Kinda worried they might complain about the downpipes
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      05-21-2022, 05:10 AM   #6
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Some on her have changed out the MAF's for new ones as a matter of course though if the rough running continues I'd take it into dealer ship to have it diagnosed anyway if it continues, it may be bad gas. If it is a leaky injector which is then replaced then you'll have to have the oil changed also.
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      05-21-2022, 10:23 AM   #7
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Common problem that could be caused by a tune too. Have you flashed it back to stock and checked?
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      05-21-2022, 10:24 AM   #8
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Quote:
Originally Posted by fstm5 View Post
Kinda worried they might complain about the downpipes
Yep, it will be a useless trip. They will say it's because of the downpipes 100%. Same thing mine said a while back.
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      05-22-2022, 05:11 PM   #9
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The cars on a stock map, isnt tuned
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      05-22-2022, 05:14 PM   #10
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Quote:
Originally Posted by M5_Raz View Post
Yep, it will be a useless trip. They will say it's because of the downpipes 100%. Same thing mine said a while back.
I figured, it's an annoying issue because it's hard to pin point what it could be, going to just change my maf's for now since these problems started ever since i touched them
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      05-25-2022, 08:00 AM   #11
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I agree that it could just be a coincidence and you have a "new" problem. That said, let's use deductive reasoning and correlation to assume your MAF's didn't like the cleaner.

Since you have the skill to remove them to clean, just replace them both yourself first. There's really no need, but once replaced, you could reset adaptations (if you have the software). Clear codes when done. Start with that IMO.

If you get codes or continue to have drivability issues, at least you know you can rule out MAF's as a suspect.
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      05-25-2022, 03:12 PM   #12
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same happened with me little rough idle but after MAF cleaning I had to order 2 new MAF sensors replaced them and that's all little rpm jumps but power is there no codes and no checks
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