2001 Cavalier Power Loss

I recently bought a 2001 Cavalier from an auction for just over $2000. It needed some work, driver's side door wouldn't open, trunk wouldn't open and was sitting incorrectly. On the drive home I noticed the car behaving very sluggishly in terms of power. Like it had 50HP. Not knowing how much maintenance the previous owner did on the car, I did usual tune-up work. New spark plugs (BOSCH Platinum +4), new air filter, new fuel filter, oil change (Pennzoil 5W-30 Full Synthetic). For some extremely stupid reason, cylinders 1 and 4 had AC Delco plugs, and 2 and 3 had some cheap BOSCH plugs. Not to metion they had rust piled in the head around them, so I had to air blast it all out with an air compressor to be able to fit my socket on them. The Check Engine light was on too. Scanning the OBD, the car had threw a code for the catalytic converter, and another for the O2 sensor. I reset the codes and have driven it around for a few days. After a few days driving, the car has gotten steadily worse. The car isn't throwing any codes and the readiness monitor isn't complete. The car steady loses power the longer it is driven. Just starting it for the first time of the day, it will hit about 25 MPH in first gear before nearing redline, 40 in second gear, and so on. Slowly, performance degrades, the car only hitting about 17 in first gear before refusing to accelerate anymore, second gear being slower aswell. The car has adequate power from pressing the gas 15 - 40% of the way, 40%+ the car actually goes SLOWER. I can barely make it up a hill in 4th or 3rd gear going 45MPH, and it will refuse to hit 60 in 5th. The car is also getting absolutely horrible gas mileage, no where near the 30+MPG you would expect from a 4 cylinder.

I had reason to believe it was the fuel pump, but performance would be bad from start up, not degrade over time. The engine doesn't overheat, but when it gets warmed up is usually when it starts acting up. The lack of OBD-II codes leads me to believe the car's ECU has failed. I KNOW this car should not perform like this, I see videos on youtube of stock Cavalier's hitting the 108MPH speed limiter with ease, mine can barely tackle 65 on a good day.

I really have no idea what it is, and I would like to confirm if its the ECU before I spend 120 bucks on one.

Car: 2001 Chevy Cavalier Base, 5 Speed Manual, 2.2L.

Note: A/C On/Off has no effect on this.

Judging by the lack of power and poor gas mileage (and the code) I would think the cat. converter is bad. I say this because the more you drive the hotter it would get, and the more performance would suffer. Easiest way to check is to drive it for a while then look underneath and see if the cat is glowing red (easier to see at night), or take it to a muffler shop and have them check it. If it is the cat then after you get it fixed make sure that you aren't running rich or have any misfires or it'll go out again pretty quickly. Good luck!

That could be true. You may want to have the fuel pressure checked. Also are you loosing coolant?

No, it isn't the converter, I know about the "red hot" thing, and it's not hot. The engine coolant is fine, and the car doesn't overheat, the water temp gauge is a little past the 195 mark as it's hottest temperature, it goes a little higher when the car is parked after driving, I'd say its about 205 - 210F. Is this normal for this car?

If you can find someone who has a tech II there might be some codes the SES is not showing or it has stored. Have you replaced the plug wires? Also a coil that is going out can cause some pretty strange problems. Just to be safe make sure the oil is not milky.

It looks like the previous owner was trying to fix whatever is wrong with it. The wires are new, and the oil is fine. If it were the wires or ignotion coil, wouldn't the car run poorly from start-up? The engine idles smoothly and doesn't sputter or misfire or anything, it just steadily loses power, and doesn't have much to start with.

My next step would be to check fuel pressure, pumps usually have a high pitch whine when they go bad. I believe Autozone will test the ecu for free. The only way to rule out the coil is to ohm it, I'm not positive what it should read on these cars but if one is a couple thousand different than the other than you know. This could very well be the coils.

By testing the ECU do you mean plugging in a scanner to check for codes, because I have an AutoXray scanner, and it shows no codes and the readiness monitor isn't complete after several days driving.

I don't think it's the pump, I can hear it when I turn the ignition to On, its a low pitched whirring sound for a short moment. Also, the car isn't suffering from gas starvation symptoms, like I said, it runs fine, but has hardly any power. I know the engine should only have like 115HP, but it feels like only 40 is getting to the ground. I'll check the coils tomorrow though. I'd be relieved if it was, that way I don't have to spend 200 dollars on getting a whole new one and getting it flashed.

Edit: Should the coils be bad, should I get the Niehoff coils or stick get the AC Delco? If Niehoff parts are reliable I'd rather spend 60 dollars instead of 100.

Also, the coolant looks kind of dingy, I don't think it should have any effect on performance though. Any ideas? I plan to flush it out.

Also, the coolant looks kind of dingy, I don't think it should have any effect on performance though. Any ideas? I plan to flush it out.
What color? it should be orange if its the dexcool.

It's like a light brown dirty color. :P

Update: Checked the coils to find that the contacts were very ugly. Rust powder poured out of the number 3 wire on the coil connector, 1 and 4 weren't great, but 2 was clean. This might explain the two random BOSCH plugs I had originally found in the car, they were plugs 2 and 3. After changing the destroyed wire and sanding the rust off the coil, I noticed a little improvement, engine response increased, and it seemed like it had a little more power, but, it gradually lost power again and went to its sluggish state, I was going up a hill at 40MPH in a 55MPH speed zone, a 4x4 hauling a trailer EASILY caught up to me. I'm getting pretty ticked off at this car. If I can't fix it by next week, I'm gonna bring it to the auction and unload it, and get a newer one with the 2.2L DOHC.

I would say change the coils and wires I am pretty sure that is the problem. If you are asking my opinion on brands I would always recommend AC Delco but.....I have Duralast wires and autolite plugs and they are not giving me any problems. I would recommend staying away from Bosch plugs or wires.

Now see I heard that Bosch plugs reign supreme in Ecotecs. I have Autolite wires. I'll check into the coils tomorrow.

Edit: Took the car on a long trip today, check engine light came on before I headed home. OBD is throwing a code for the engine running rich (bank 1) and catalyst emission system performing below a certain threshold. Almost didn't make it home, the final hill on the way to my house has a long stretch of road before it, even with the stretch I was barely able to keep 35MPH up the hill (55MPH speed limit).

The car is pissing me off to an extreme. I'm probably going to take it to the auction and try to get some money back, then get an '03.

I just don't like Bosch. I haven't had the best luck with them. I'm sure there are some advocates for them, just speaking from my own personal experience.

Well you should try some Bosch Platinum plugs the next time you change them.

lol. I just might do that.

Alright, I'm going to replace the catalytic converter and the MAP sensor. If that doesn't work, I'm selling. Getting to the MAP sensor is a pain in the first place. I've seen people wih the P0172 code having MAP sensor failure, so why not try it.

Update: Alright. I solved the problem. I ordered a MAP sensor from my local Advance Auto Parts, and they'll have it tomorrow. Driving home, the car decided to kill itself, so I was driving home on the shoulder with the hazard lights on at a speed no more than 30MPH. I made it home and popped the hood, inspecting the engine. The coils weren't hot, and nothing was smoking or burnt or anything. Scanned the OBD with my tool, and got the P0172 (running rich) and P0420 (catalyst efficiency below threshold) again. Revving the car lead to sputering and crapping out at about 2000 - 3000RPM (the car has no tach, so I'm only guesstimating). For kicks I took out the upper oxygen sensor and started the car again. It ran EXCELLENT. I'd like to note that one should not remove the upper oxygen sensor and rev their car to a high RPM unless you like hearing loss. I closed the hood and decided to try to see if it would make it up the nearby hill at my house. The car has power I've never seen before. I was in third gear at 55MPH going up the hill and the car wanted to GO. So, plugged converter all along, caused by the MAP sensor making the car run rich. Oddly enough the converter wasn't hot or red at all. I ordered a Magnaflow converter and I'll be expecting that in a few days. Thanks for all your input and help, Jason.

Alright. The car is fixed. It hauls ass with that new converter. MAP sensor installed and my P0172 is gone. I cleared the codes and we'll see what happens.

No, it isn't the converter, ..................................
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