After my "Service Engine Soon" light came on this morning on my 1999 Mustang V6, I took it to autozone and the lady told me that the PCM was going out and the O2 sensor was out. I really want to know how severe these things are and the estimated cost to fix them. Please help.

 

Replace the 02 sensors and it may be good to go. It's not an expensive fix.

 

Without knowing the exact trouble codes it is a bit premature to start throwing parts at the problem.

CubaKid702, post up the exact trouble codes the lady at AutoZone pulled from your car. Then we can narrow down the problem & give guesstimates about how to fix & cost. O2 sensors are relatively cheap but often difficult to replace. PCM's are expensive and easy to replace (unless they require programming).

 

We also need to know any modifications that the car has. It's extremely common to get an O2 code when the real issue is a K&N type filter that the oil has gotten on the MAF, and the way to fix it is spraying the MAF with brake cleaner.

 

The lady didn't give me the codes. I'm going to check it again on Wednesday with my mechanic. I'll let you guys know specifically how it went. Thank you guys so much, I really appreciate it. Let's hope my pony gets better