Engine Performance problem
1992 Buick Lesabre 6 cyl Front Wheel Drive Automatic 176--- miles
Okay, so, starting from the beginning. Unfortunately it's going to be long to kind of give you an idea of what I've replaced and all the prblems. A couple of months ago my car just wouldn't start up. I believe that my lights were left on and then eventually my alternator died. I bought a used one from a junkyard and that has been fine ever since. Then it happend again and found that my ignition coils went bad. Replaced those and then my car was fine for maybe about a month. I then found that my car began to have a rough idle and it kept shutting off on me and then wouldn't start back up until it cooled down. I thought that maybe my ignition module went bad, so I replaced that. That didn't work. Then I started to get a hesitation while accelerating and thought that I needed a new Mass Air Flow (MAF Sensor), so I replaced that. That didn't work so I decided to take it to the shop. They ran the diagnostics, found no codes, cleaned the fuel injectors, Idle Air Control Sensor (IAC) and the Throttle body. That worked for maybe a couple of hours then it happend again (the rough idle, stalling, longer start-up, acceleration hesitation). I got it towed back to my house and researched of the reachable parts connected to my engine and the symptoms of bad IAC, TPS, MAF, Throttle body, and checked to see if there were any MAJOR leaks of oil or anti-freeze. I found that a bad TPS will cause all of the problems listed above, so I changed that (and yes, I do it myself. No need in spending money on labor when you can read a repair manual online). The car does not shut off anymore, but the rough idle and hesitation are still present. Now, to the question. Can a bad EGR valve cause either or both of these problems or maybe the catalytic converter? Does anyone know what can be done to fix the problem?