So I'm completely stumped with the wife's 2000 GTP. When I give it gas it takes off just fine until it hits about 20 mph and 2200 rpm's, then it falls flat on it's face. If I hold it to the floor, it will gain speed and a little more rpm till it hits 3000 rpm but so slow that I hardly notice it. I am however able to hold the throttle at a position around 2000 rpm and the car will gain speed at a normal rate too the speed I want but obviously at a rate that makes the drivers behind me not to happy. If I put it in neutral, the rpm's will go up to 4-5000 without a problem but nothing more. This did happen a few times this last summer and it seemed if I mashed the pedal to the floor for about 10 seconds it would fix/clear or whatever the problem, until now where I just can't get it to stop doing it. I have had it in the shop and they did a complete diagnostics check on the engine and found nothing wrong. Could this possibly be a torque converter issue? Plugged catalytic converter? I am open to any suggestions. Thanks in advanced guys.
Completely Stumped
- Thread starter Hyrdgun
- Start date
SlowNA06
New member
Bad spark plugs (remove, check now. Copper = 15,000 mile item, iridium = 100,000 mile item, platinum = misfires, bosch, champion, e3=misfires)
Massive vacuum leak - check all hosing, especially on passenger side of lower intake manifold
Clogged cat (this bad, you'd totally notice the rotten egg smell) (150,000+ mile item)
Dirty Mass Airflow Sensor - just clean this with CRC mass airflow sensor cleaner
Gummed-up throttlebody - just clean this with throttlebody cleaner. Toothbrush might help.
Intake filter clogged with leaves (30,000 mile item anyway)
Clogged fuel filter (30,000 mile item anyway)
Clogged/broken fuel injectors
Massive vacuum leak - check all hosing, especially on passenger side of lower intake manifold
Clogged cat (this bad, you'd totally notice the rotten egg smell) (150,000+ mile item)
Dirty Mass Airflow Sensor - just clean this with CRC mass airflow sensor cleaner
Gummed-up throttlebody - just clean this with throttlebody cleaner. Toothbrush might help.
Intake filter clogged with leaves (30,000 mile item anyway)
Clogged fuel filter (30,000 mile item anyway)
Clogged/broken fuel injectors
rocknnachos
New member
What happens at 20mph? Does the engine run rough at all? Would you compare it to driving a manual transmission car and shifting from first gear to fifth gear instead of second gear? Does it seem to shift through all the gears fine but it just takes long to get up to those speeds?
thegipper
New member
Could be a clogged cat. You can unscrew the O2 sensor before the cat and secure it somewhere temporarily. Then drive the car around and if it drives better (now that the exhaust gas can escape through the O2 sensor hole). If it drives fine, get your self a new cat. Good time to get a downpipe with a ubend delete w/ a new cat.
Good luck
Good luck
SlowNA06, I have checked or replaced all the suggestions you gave me with the exception of the fuel injectors and the cat. At 20 mph/2200 rpm it just does not pick up speed anymore. It has that feel of still getting fuel but just does not want to go, but the tranny is not acting like it is slipping and the rpm's won't increase. If I sit in the driveway in neutral or park, the rpm's will get to about 5000. Doing the same in drive or reverse the rpm's will only get to 2200. I think I will try thegipper's suggestion of pulling the O2 sensor and driving it. A guy at work suggested doing the same but then also doing a back pressure test. Thanks guys
Nicksupercharged
New member
Definately sounds like a clogged cat.
Well, here is an update. I just happen to run into someone who was having the same problem, only on his Tahoe. Turns out that the sensors for the traction control were very dirty, and after cleaning them, it ran fine. I went out and unplugged one of the sensors, which turns off the ABS/Traction Control System, And wouldn't ya know, the car runs great. Now I just need to figure out which sensor is bad since I don't think I can pull mine out to clean.
cheap 98 gt
New member
sounds right, rpm limiting is a common traction control function, good info., would not have thought that
BlackGT97
New member
i just had the same problem today. couldnt figure it out until i seen the low trac light was on. then im like "oh, its cutting the timing". so i just turned off the traction control and the problem was fixed. some how the computer thought the wheel were spinning and cut the timing....never heard of that until i experiaced it today.