My daughter and her husband recently purchased a new car and gave me their 1998 Mercury Mystique LS Sport 2.5L V6.
When I attempted to inspect it in NYS, I was told that it would not pass inspection because the Check Engine light was on. I was further told that there was such a laundry list of possible causes to invesitigate that "it might not be worth it to me to proceed."
Say what? I should just junk the car because of a "Check Engine" light? No freaking way! Needless to say, I took the car home.
The inspection report stated that OBDII diagnostic codes P0171 and P0174 were present. I began to investigate these codes via the web and found several resources of valuable information, especially including this forum. Following a bit of sage advice I encountered here - try the simple first - here is what I did:
Incidentally, I am a total novice so bear with me...
I first located the Mass Air Flow (MAF) sensor between the air filter compartment and the ??intake manifold?? I discovered that I would need tamper proof star bits to remove the MAF. Off I went to the Advance Auto Parts store. For $22 I purchased the start bits, electrical contact point cleaning spray and a new air filter.
Opening the air filter compartment, I discovered what must have been the original 1998 air filter. It was so dirty that no air could possibly flow through it. Dirt literally fell off it in clumps and the compartment was full of sand and pine needles. I cleaned everything up and installed the new air filter.
Next I removed the MAF sensor. It did not look particularily dirty but one of the tiny wire coils did look a bit discolored. I thoroughly spray-cleaned the two wire coils using the contact point spay cleaner employing the furnished straw to direct and concentrate the spray on the wire coils. I then replaced the MAF sensor.
I do not own a diagnostic unit, so to erase the stored OBDII codes I disconnected the battery cable and went for lunch. After lunch, I reconnected the battery cable and started the car - no "Check Engine" light of course. I took the car out and up the highway for a 20-mile round trip and shut it off. I restarted it - no "Check Engine" light. Twenty minutes later I repeated the same trip, shut the car off and restarted it - no "Check Engine" light.
I drove the car again later today and still no "Check Engine" light. Tomorrow I will take the car to have the inspection completed at no further cost than the NYS fee. Had I owned the proper bits and the spray, my only added expense would have been the $7 air filter.
Needless to say, I will not visit the same inspection station again.