Rough rough idle at cold start?
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From: Marshalls creek PA
Rough rough idle at cold start?
Hey guys, quick question. Yesterday I got tuned and whatnot, cat warm up cycle was disabled, and last night leaving work and this morning leaving home, on a cold start when I start it up, the car sounds cammed along with a jerk every few seconds basically sounds like its on its last leg, soon as it got to 127* it stops and runs normal... now is this normal without the cat warm up?
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Joined: 04-18-20
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From: wilmington IL
Hey guys, quick question. Yesterday I got tuned and whatnot, cat warm up cycle was disabled, and last night leaving work and this morning leaving home, on a cold start when I start it up, the car sounds cammed along with a jerk every few seconds basically sounds like its on its last leg, soon as it got to 127* it stops and runs normal... now is this normal without the cat warm up?
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Joined: 02-13-22
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From: Alabama
Hey Everyone. New here and cant for the life of me figure out how to post a new thread here. so sorry for hijacking in advance.
05 Cobalt SS/SC I just got the car a little over a month ago. P.O said it needed a alternator. I tested it once I got it home and it was good Im assuming he had a dead battery cell. also all the car originally had for a exhaust was ZZP Shorty Header, 3" cat delete down pipe, with the 3" collector welded directly to a Glass Pack with a 3" magnaflow muffler welded to it and a Injen CAI. it was super Loud (still is just not as bad). Anyways I cut the magnaflow free from the glass pack. And finished running 3" pipe out to the rear of the car and rewelded the magnaflow at the rear bumper. Car was still running good. about a week later I decided to Change the oil, air filter ( Discovered it didn't have 1 to begin with), and put a new set of plugs in it. Reason for tune up was I noticed it had a odd idle almost like a cam loping all that cleared up emiditly. Now a week or 2 Later at cold start it started having a horrible erratic idle. once up to around 180-184 it smooths back out. but for the life of me I cant figure out WTF is causing it. I have no codes and yes I have checked with my Scanner. TO THE BEST OF MY KNOWLEDGE THE CAR HASNT BEEN TUNED. I did check the ecm for a sticker it looks like it had 1 at some point but its not legible. just looks like a white square sticker about 2"x2" then of course all of the factory oem labels. ANY HELP WOULD BE GREATLY APPERCIATED. Before I say screw it and start replacing every sensor under the hood. I'm seriously considering going ahead and replacing MAF,MAP, both 02's, T.B, intake and exhaust gaskets along with the PCV or whatever its called in the intake. Because I'm Completely stomped and not sure what to do at this point.
things I've tried so far
cleaning MAF with crc MAF cleaner
cleaning MAP with CRC
doubled checked plugs
checked for vacuum leaks
checked for manifold leaks
checked for exhaust leaks
05 Cobalt SS/SC I just got the car a little over a month ago. P.O said it needed a alternator. I tested it once I got it home and it was good Im assuming he had a dead battery cell. also all the car originally had for a exhaust was ZZP Shorty Header, 3" cat delete down pipe, with the 3" collector welded directly to a Glass Pack with a 3" magnaflow muffler welded to it and a Injen CAI. it was super Loud (still is just not as bad). Anyways I cut the magnaflow free from the glass pack. And finished running 3" pipe out to the rear of the car and rewelded the magnaflow at the rear bumper. Car was still running good. about a week later I decided to Change the oil, air filter ( Discovered it didn't have 1 to begin with), and put a new set of plugs in it. Reason for tune up was I noticed it had a odd idle almost like a cam loping all that cleared up emiditly. Now a week or 2 Later at cold start it started having a horrible erratic idle. once up to around 180-184 it smooths back out. but for the life of me I cant figure out WTF is causing it. I have no codes and yes I have checked with my Scanner. TO THE BEST OF MY KNOWLEDGE THE CAR HASNT BEEN TUNED. I did check the ecm for a sticker it looks like it had 1 at some point but its not legible. just looks like a white square sticker about 2"x2" then of course all of the factory oem labels. ANY HELP WOULD BE GREATLY APPERCIATED. Before I say screw it and start replacing every sensor under the hood. I'm seriously considering going ahead and replacing MAF,MAP, both 02's, T.B, intake and exhaust gaskets along with the PCV or whatever its called in the intake. Because I'm Completely stomped and not sure what to do at this point.
things I've tried so far
cleaning MAF with crc MAF cleaner
cleaning MAP with CRC
doubled checked plugs
checked for vacuum leaks
checked for manifold leaks
checked for exhaust leaks
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Sep 26, 2015 12:16 PM