QuestionQUESTION: Hey James, been having quite a bit of issues with my car lately.
First off, I have had both of my O2 Sensors replaced a lot (front one 4 times, rear twice) and every time (within about 200 miles) my check engine light comes right back on. It's gotten to the point that my mechanic will not replace it again until I get someone to take a look at the electrical. Is there anything you know of that could cause the O2 Sensors to constantly blow?
Secondly, the car is idling at 1500rpm. I've already replaced the IAC Valve and that didn't fix the issue at all. Is there another part that could causing this?
Third, whenever i turn on the ac compressor, my rpm's drop to 750 and the car doesn't compensate for it. I was told that the compressor needs to be replaced and, since I can't afford it right now, was just unplugged until a later date. About 2 days later, my car started overheating (the fan won't turn on until the very last second, right before it hits the red). Everything in regards to the fan has been checked or replaced and everything seems to be working right, however; today I just found out my blower motor is blown. Could this be causing both the idle speed drop and the overheating (since the compressor is unhooked)?
Thanks for your time.
ANSWER: A mass air flow sensor will sometimes pull a O2 trouble code without the O2 actually being bad. The car needs to be scanned using something more that the $10o special from the parts store. I recommend finding a mechanic with a Genesis scanner like I have. A descent one runs around $5000. So when you are asked to pay the $75, don't get sticker shock(prices may vary). Also, most of the time, if I do the labor, I will waive the fee. I myself find that their are times that I outsource to Automotive Electrician. Think of these guys like medical specialists. Kind of like a garage that just does transmission, exhausts, etc. Of course they charge a little, but in the long run it is well worth it. And of course, the problem is fixed. Now as far as your idle goes, 750 is an acceptable RPM with the compressor on. However, 1500 is not which is another reason why I suspect the Mass Air Flow. If you Pull the trouble codes at your local parts store I can probably confirm this. The overheating is troubling. I recommend that you do not drive the car until this is resolved to prevent catastrophic engine failure, if not already applicable. You may want to start with a coolant system service to start with and or a thermostat replacement. I certainly would while flushing the system.
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QUESTION: Ok, sorry. i should have thought about this on my first post. this is everything that has been replaced since 3/24: mass airflow sensor, transmission, radiator, both O2 sensors, thermostat, iac valve, coolant fan switch, both fan relays.
There has been many more repairs including coolant flush (around $9500 in costs since march), just most don't deal with issues. also, aamco also said same thing about the codes w/ their $8000 system, though i remember autozone saying something about since two codes came up, it wouldn't be the mas. anyways, awaiting your reply. Btw, its a 2.0 v4.
AnswerUpon further consideration I have the following theory. The overheating issue is the culprit. When the temperature gets outside of normal operating temperature, the computer tries to compensate. Just the fact that the fan does not cut on until the car is near the red says it all. Look in your yellow pages and find an automotive electrician. I am sure that you won't find this much help. However, believe me, it is where the car needs to be. The sensors have to be read, along with what is actually happening with the car. The only thing that I can honestly think is that they do not fully know how to use the scanner.
