Check engine lights on?

The engine picture service light comes on and off, obviously I should get a diagnostic, but ive been having rough idling with turning. And a major problem is in full throttle it sounds like its hitting the rev limiter near 4000rpm, however it runs smooth unless I tromp it, kinda like misfiring

Hello! My check engine light came on today when I started up the car and the dashboard lights were flickering and eventually went out completely. When I tried to accelerate, the car had very little acceleration. The RMP went up to 4 when I accelerated to 15mph.I just had work done on the car a couple days ago and paid over 1,000 ;(

Hi! It's an automatic. I had some break work done and there was a leak in the gas tank. It starts and runs, but when starting it feels as if it has a weak battery and not much power.

I put new coils new spark plugs new ignition module and the check engine light still blinking on and off and just there on the dash. The fan runs real loud while driving and it is shaking and it feels like it want to turn off especially when in reverse. It had a smell when I turn the car off.

Just this Sunday on a road trip from Florida now in the high elevation of Yellowstone, the check engine light came on, the car was intermittently losing a little power, idling weird, and black smoke was coming out of the tail pipe. Yesterday, I took it to a mechanic. The code stated the fuel mixture was rich. We replaced the original spark plugs, cleaned the K & N air filter, & checked fuel pressure. After he finished and cleared the code, it seemed to run fine the rest of the day. Then this morning, the light came back on and the same symptoms reappeared. Before we left for the road trip, we had the fuel filter replaced. We also recently had a fuel system cleaning performed and the fuel pump replaced. My next guess would be a sensor?

One more thing about a different issue. About a week ago as we were pulling in to Mt. Rushmore, the puller fan blade fell apart. I unplugged the fan and continued to drive short distances around the campsite while I waited for the new part to arrive. I watched the temp gauge and it never rose higher than normal. The pusher fan was running on high speed. I figured it was because the puller fan was disconnected. I installed a new fan assembly when it arrived, but the pusher fan on the radiator is still running on high speed 95% of the time, even when I first start it in the morning. The coolant system was flushed before our trip and the level is currently good. Not sure why it stays on high, but it's very annoying especially when it's 30 degrees outside.

Can a dirty air filter cause a "Check Engine" light on a Saturn L200 to go on?

I brought it to a car parts store and they performed the test. They said I need a new O2 (or L2), can't remember, upside or upward. Costs about $53 and they said it was fairly easy to replace myself. Do I have the right terminology?

Today, I noticed my car was lagging & the service engine light came on. It stayed on the entire time I was driving roughly 30 minutes. I read the manual & it stated that gas cap might not be on tight. I check that & gas cap was on. Light is still on. I have been using 87 octane for gas consistently. I'm not sure what could be the problem. I always get my oil changed & every other oil change I put in the fuel systems cleaner. I feel as though I take pretty good care of my car. Any suggestions would greatly be appreciated.

What does mean when the car power go dawn when you pushing gas, feel like something pulling you from the back the gas gage it dont move, the service and engine soon service lights come on after somebody try to check if the copressure works or not by hooking wire between the battary and the fuse box under the hood and the compressure.