Purchased my daughter a 01 grand prix 3.8 101k. Car seemed great but we know how teenagers drive tsk tsk. Last week she came to me saying her car was running poorly but I'm sure it has for some time. O figured I would fix it and if I couldn't I'll take it to the shop. First thing when o took it for a cruise. No CEL. It stumbled thru the gears. Trans seemed to kick it when it could. But I would REV without getting much speed or power. Car would top out at 50ish. Sometimes o could get it up in the 70s and 80s but without any power. Thought Trans or Cat failure. Decided to unplug the battery and see if codes would reset. Came back with EGR fault. Took it off and cleaned it. Came back with random misfire and o2 sensor. Found a vacuum leak in the manifold. Sealed it up then codes went away. But still have the issue I had before. Anything else I should look at before I take it into the shop?
No Power thru my shifts.
- Thread starter akito
- Start date
BillBoost37
New member
Reading what you wrote here's what I read, I'm sure I misread a bit:
1. Daughter has a 3.8L (unsure if supercharged or not) that runs poorly
2. You stated no CEL and engine seems to stumble
3. Trans seemed to kick it when it could (What does this mean?, I'm not understanding this at all)
4. You could rev w/o getting speed or power. This sounds like a slipping transmission.
5. You unplugged the battery to reset the codes. If #2 is right, there were stored codes that had not set the CEL? What were the code numbers and code descriptions? This will be a huge help to understand what may be happening.
6. EGR code... depending on which code, it might not be EGR related. There is an EGR insufficient flow code that typically is a bad map sensor because it's trying to read if the EGR flow changes when commanded open/closed.
7. You fixed a vacuum leak and the codes cleared themselves or just haven't reset yet? Codes can be current, history and/or stored. This again is a symptom and might help.
8. What issues are still there, the slipping feeling, skipping engine (misfires), lack of power?
Please try and explain a little more as it could help us get you fixed up quick.
1. Daughter has a 3.8L (unsure if supercharged or not) that runs poorly
2. You stated no CEL and engine seems to stumble
3. Trans seemed to kick it when it could (What does this mean?, I'm not understanding this at all)
4. You could rev w/o getting speed or power. This sounds like a slipping transmission.
5. You unplugged the battery to reset the codes. If #2 is right, there were stored codes that had not set the CEL? What were the code numbers and code descriptions? This will be a huge help to understand what may be happening.
6. EGR code... depending on which code, it might not be EGR related. There is an EGR insufficient flow code that typically is a bad map sensor because it's trying to read if the EGR flow changes when commanded open/closed.
7. You fixed a vacuum leak and the codes cleared themselves or just haven't reset yet? Codes can be current, history and/or stored. This again is a symptom and might help.
8. What issues are still there, the slipping feeling, skipping engine (misfires), lack of power?
Please try and explain a little more as it could help us get you fixed up quick.
Sorry to ramble. I think the code for egr was 0401. I ended up cleaning it out with carb cleaner and unplugged battery. Heard a leak in the manifold. Something melted on it near the throttle body. I used a plastic welder I also changed the plugs and wires. Codes for the random misfire and o2 sensor cleared. But still have these performance issue. It could be transmission related. It's a non supercharged 3.8. The rpm gauge seems to rev higher than it should without the increase in mph. I can't redline it tho. Speed comes to a halt around 50 mph. I can get it up to higher on the highway but takes a long period of time. It doesn't have power to overtake any other vehicles. I haven't found any stored codes or what not.
BillBoost37
New member
P0401 is insufficient flow. Unless you found a sticky or cruddy egr, it might have something to do with MAP sensor. I'd hold off and see if it comes back thought.
Do you have a way to scan for misfires in real time while driving? Seems that you might still have an issue there. Which can also feel like a trans issue.
Do you have a way to scan for misfires in real time while driving? Seems that you might still have an issue there. Which can also feel like a trans issue.
So far no codes a few e being thrown the car has not much power took it to the shop. They looked at it and wanted to replace the entire exhaust for about 1k. They said the flow of the cat seemed good bc of the in and out temp and they thought maybe something was plugged up downstream. Might try and take it to a exhaust shop and see if they can figure something out. They also checked the fuel pump and some other things and said it all came back fine...
71gs3504sp
New member
How about just disconnect the exhaust after the cat and see how it runs!
If it runs good after the disconnect then it the exhaust.
If it runs bad after the disconnect then your back where you were and didn't spend 1K for an exhaust.
If it runs good after the disconnect then it the exhaust.
If it runs bad after the disconnect then your back where you were and didn't spend 1K for an exhaust.