2002 Pontiac Grand Prix Service engine light

117,000 MILES • 6 CYL • FWD • AUTOMATIC
Avatar
STOCKLIN
  • MEMBER
  • 4 POSTS
My service engine soon light came on and yet my car is running perfect. I average 26 mpg in town and 31 hwy. I get my oil changed every 2500 miles. In fact I just had it changed 1000 miles ago. I did put in ethanol blend gass, which I always use, but someone told me to use regular so when I had a 1/4 tank of gas left I put in regular--after that and about 350 miles later the service enging soon light came on. What causes that and what does it cost to repair?
Aug 26, 2008 at 5:57 AM
Advertisement
Avatar
MMPRINCE4000
  • ✓Experienced Mechanic
  • 8,548 POSTS
Take the car to any auto parts store and have the codes read (you need a scan tool to read the PCM codes). This is a free service.

Cars since the mid 80's are designed to run on 10% ethanol.

Only Flex Fuel vehicles are designed to run on E85 (85% alchohol).

The SES light could be something as simple as a loose gas cap. Get the codes read and let us know.
Aug 26, 2008 at 8:12 PM
Avatar
ACE HIGH
  • MEMBER
  • 2 POSTS
do it your self and go buy a obII diagnostic code reader.this will tell you whats wrong and you can reset the engine light.the plug in for basically all vehicles are underdash right hand side.be sure to plug in with car off,unplug with car off.never never start car with obII plugged in.a cheap one is about 50 bucks.
Oct 5, 2008 at 2:34 PM
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Frequently Asked Problems for This Vehicle