My 2002 Isuzu Troopers Check Engine light and Reduced power light came on and the engine ran very slow and sluggish. Checked the next day and check engine light came on and Reduced power light was no longer there. Had computor diagnoses and codes P1295 and P1515 showed up. After computor check, check engine light went off and I've had no more problems, but don't trust it to drive very far. What would be the most ovious problem?

code p1512 refers to intake manifold runner control stuck closed
replace it or remove it and clean it

Where I live there is a Schuck's auto parts...and they have a hand held diagnostic tester that plugs right in to your harness. This will tell you whats is wrong.It only takes about 2 min and they don't charge you.On my car it was the mass air flow censor.If you can't find a Auto parts store that does this...take it to a shop soon. Good Luck

That has happened to me before. I parked the truck, turned off the engine, waited for about 5-10 and restarted. As long as the reduced speed indicator and/or the check engine light don't remain on you are good to go...hope this helps

Try adding gas line antifreeze to your fuel. If you have water in the gas, this will clear it up. Water in the gas line can turn to slush or even ice when the temperature dips below freezing, causing reduced power because of reduced fuel flow.

I have the same problem. But my check engine light comes on when this occurs. The car runs fine otherwise. The problem manifests when it's hot out and I've been driving for a while with the A/C on. When I stop somewhere (like the supermarket), shop, and get back in my car. It starts fine but when I put it in gear to go, it's extremely sluggish for a few seconds and the check engine light comes on. Then is runs fine but the check engine light remains on. The next day when I start it, the check engine light is not on. Also, I recently had the head gasket replaced. I took it back into the shop the first time the check engine light came on. The mechanic checked it and said everything checks fine. He re-set the light saying to keep an eye on it and bring it back in if the check engine light comes back on. It ran fine for 1.5 weeks and now this problem has started to occur.

Did you find anything out dwbradway? I wish I had a solution for you but I just have the same kind of problem. Any help would be appreciated!

check and see if you may have choked off your exhaust.

Try changing fuel filter

reduced power usally points toward a gas pedal to throttle correlation meaning the drive by wire system is where the problem is

I'm having same problem on my 2000 model rodeo 4wd 3.2L V6. Other day check engine light came on. I checked engine bay nothing abnormal, or power loss. Next day light was gone. 2 days later driving, a sudden loss of power and light came up. After idling for a couple of minutes, drove off with light still on but all power back. 1 hour later of faultless driving loss of power for a minute or so. Engine temp normal. Had break for 1/2 hour and set off for last hour of journey without fault except check engine light still on. Following dayon startup light went out???
Seeking help from experts.