Check engine light on?

I have a 98 Mitsubishi eclipse gst my car reaches 80mph and it cant go any faster it stays their at 80 and I thought it was weird because I have a turbo and for the car to just go 80 I thought it was weird because it usto reach 140 and im guessing its the ECU but im not sure. Please help 2carpros

I have a few questions for you. Does the car reach redline? Automatic? Stock turbo/wastegate/blow off valve?

Yes it has a Stock everything including turbo and blow off valve. It does not reach redline and it is standard, like I said just hits 80 in 5th gear no higher and the rpm stays at 4 or 5.

I have a 1998 eclipse that runs fine until I go up a hill. Then the check engine light comes on, car jerks, makes a pop noise and I loose overdrive and drive. Remove battery cable, reset computer and everything is fine until the next hill. This doesn't happen at a slow speed, only at higher 50-70mph speeds

Had to drive it for about 50 miles to get them to come up again, but I got 2 of em the first came up as a pending code 0700 (transmission control system), the second was code 1776 (drivetrain power) But it does not happen on hills, we drove it up and down some 10% grades and it worked fine

Anybody?

In order to remove the check enginer light from my car to pass California SMOG, I used a diagnotics tool to reset the computer. After driving for over 400 miles in stop/go plus freeway conditions, none of the 5 non-continuous tests have been marked as complete. 2 years ago I was able to reset the computer, and after a week the SMOG went through with 3 of the 5 tests being marked complete. Any suggestions on why the computer has not completed any of these tests?

I wouldn't believe that code. The trans won't kil the motor. But you must be mechanical -- you figured out how to reset the PCM and get it going again.

Spend Saturday afternoon with it and check the basics: trans fluid first, then fuel resssure, pull the plugs and check their condition, check compression (engines that are worn out have problems with hills, maybe that doens't sound like your motor), clean the EGR, take off wires and check the conections, especially grounds, check O2 sensors, treat it to a new air filter, clean the plenum, replace old crappy vaccum lines, change the oil, etc. Some of that is totally unrelated but all of it is good stuf to do on an older car.
You very well may fix and never know what the problem specifically was.

The code was P0421 "Warm Up Catalyst"
I was able to pass last time with 3 of 5 tests being complete (obviously not the cat test), but this go around I haven't been able to complete any of the tests. Any suggestions?

I have a 1998 Mitsubishi eclipse gs it had a cylinder 3 misfire in it so I replaced spark plugs and wires and coil pack. So I finally had to break down and buy a valve to do a head job that fixed the misfire and the check engine light went off. For about a day then it said cylinder 2 misfire and cylinder 3 misfire but it doesn't sound like it has one please help really don't want to go through another head job

Yes all valves were fine except the cracked one and yes we did they all had good compression except 3 it only had 70lbs before it

I've had my car for about 5 years now. With in the past year, we found out there is an oil leak, but we are unsure where the oil is leaking from. About a week ago, I was driving home, and realized my temperature gauge was a little high, so I popped the hood, and the coolant was low. No big deal I thought, so I had it filled. The next day, I was driving, and my check engine light came on. On my way home, I stopped at a red light, and the temperature started to rise again higher then normal (check engine light still on), but as soon as I would give it gas, the temp would go down. My boyfriend drove it around back roads the next day, and even let it idle for a good 20 minutes, and nothing happened. Now, a week later, the coolant has to be filled about every 3-4 days. Help! I don't know if it's engine problems from running on low oil, but we haven't taken it to a garage to get looked at yet because we wanted to fix it ourselves. Any advice would be great, thank you for your time!

I had just baught a 98 eclipse for the winter and I just put it n the road. I been driving it all day and the check engine light came on. I figured it would come on because it sat for a year and a half and the battery was dead. But my question is the light will flash at higher rpms. My first thaught was maybe the knock sensor but the car is not knocking and there is oil in it. What could it be.