Check Engine Light

Maintenance/Repairs
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1

I drive a 1995 Crown Vic (not police) and the chk engine light is on. The light has been on since we got the car about 4 years ago. The car has 88,000 miles on it now and had about 31,000 when we got it. The car was not driven for about 6 years before we got it. There are 2 codes in the computer: 1) rich condition R bank and 2) rich condition L bank. The car runs smooth and has power and gets about 21-23 miles to the gallon regularly. A dealership tried to fix it but could not pinpoint the problem. I can put the light by disconnecting the battery but the light will come back during a second trip. I just want to get the light out. I have not replaced oxygen sensors (there are 4) and the dealership did not recommend doing so. What the heck could be causing the rich condition?

2

You may have a rich condition or the computer might just think that you have a rich condition. Either way this could be from too much fuel (or signals that say so) or not enough air (or signals that say so).

Pull the spark plugs and look to see if they show signs that you are actually running rich.
If equipped, clean the MAF sensor.
Check for vacuum leaks.
Test the fuel pressure and fuel pressure regulator.
Check for exhaust leaks.
Someone with fancy equipment can check out the O2 sensors.

3

Does the 1995 have the computer?

 That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.
4

Thanks. I believe codes are 0173 and 0177. Reading the codes has been done. I have checked the simple stuff several times without finding an issue. If a Ford dealership can’t find the contributors how can I find it?

5

If you have been driving it for four years and 57000 miles and it is running fine and getting good gas mileage why are you worrying about it now? If it starts running badly, pull the codes again and concentrate on any new ones. If the light bothers you put a piece of black tape over it.