O2 question
Thread Starter
On The Tree
Joined: Sep 2008
Posts: 195
Likes: 1
From: Newark, Ohio
O2 question recently my car has been running hit or miss. i fire it up and straight fuel from the exhaust and idles real low. once that sorts out then after about 30-40 minutes of driving it starts hesitating under light throttle. then if i put it in neutral and let it coast while it's having fits it'll idle super low and almost die. i noticed the other day my front pass o2 came unplugged and didn't even throw a code. so i plugged it back in thinking this would solve the problem. it didn't. bad o2? runs the same unplugged as when plugged in. still doesn't explain why it wouldn't just run like **** all the time.
These PCM's will try to adjust things for a little while, then it will switch to SD tune. When both of my 02's were bad from the car sitting for 4 months....I would start it up, it would run like HELL for about 3-5 minutes...then smooth right out. Then occasionally after it was up to operating temp it might try again for a few seconds, then go back to running perfectly fine.
I've been in and out of town the past few weeks and haven;'t been able to deal with my issue......buit I think I bought a bad "new" sensor and when I start my engine now it runs perfect in closed loop, then when it tries to switch to open loop while its warming up it breaks up so bad it will not accelerate and feels like the engine is falling apart...then about 20 seconds later the PCM clears things up and it runs 100% perfect all day...till I shut it down again.
These things are wacky man........these PCM's are still not totally figured out, not even by the most experienced tuners and computer geeks.
.
I've been in and out of town the past few weeks and haven;'t been able to deal with my issue......buit I think I bought a bad "new" sensor and when I start my engine now it runs perfect in closed loop, then when it tries to switch to open loop while its warming up it breaks up so bad it will not accelerate and feels like the engine is falling apart...then about 20 seconds later the PCM clears things up and it runs 100% perfect all day...till I shut it down again.
These things are wacky man........these PCM's are still not totally figured out, not even by the most experienced tuners and computer geeks.
.
I'm tellin ya....PCM's are all not created equal. I unplugged my MAF a couple weeks ago and went for a drive, never threw a MAF code......
Strange joo-joo............
.
TECH Fanatic
Joined: Jun 2006
Posts: 1,285
Likes: 1
From: Elgin, Il
Its not that PCMs are different but EACH dtc has its own very specific criteria that needs to be met to set. Then it has its own amount of times it needs to set to light the MIL. I had a Suburban yesterday. MIL on, throwing 2 MAF codes and 1 MAP code. Pulled it in, scanned it, read some freeze frame data, when I started it back up the MIL was off.
Trending Topics
10 Second Club
Joined: Jan 2010
Posts: 2,317
Likes: 20
From: Hurley, VA
If I unplug my MAF my car won't back out of the driveway. Never unplugged an 02 sensor but when they were bad it never acted any different. Also on my trans am a friend of mine cut a wire going into the computer that kills the check engine light bulb. No light but it still stores them in the computer, for the longest time I had a code for a ground and I could not figure out what it was but it turned out to be the wire he cut itself.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
