Hello I just recently bought a 03 CTS 3.2 for my fiance from a private seller with 53,000 miles a couple weeks ago,I noticed it just had the oil changed at Tuffy,it was his wife's car and the warranty ran out so she just stopped anywhere to get the oil changed.No big deal I hope,well I finally had the time to change the oil yesterday myself. I used Mobile 1 10w30 synthetic which was probably never used before in this car.Ok my question is would this have anything to do with the check engine light coming on tonight on her way home from work,switching to synthetic?Thanks

 

Just some background on Check Engine Lights. They only exist because of Governement Regualtions and emmission control laws so for the vast majority of situations the light comes on because it is monitoirong the emission system and the computer detcts something that is not up to specification. So the system is looking at air, fuel ,spark primarily. The name Check Engine Light is misleading imo but no doubt the car companies and dealers like this name because people come running back to the dealership every time it lights because it scares them due to the name.

As an aside, we have a friend who is a factory mechanic for Ford and his job is post production detail and repair. He works in the plant that builds Police Interceptors. He tells me that many cars come off the end of the assembly line and when they are started the Check Engine Light will come on., his job is to find out why and repair. He finds things as varied as a gas cap that was nicked with the air gun during installation or a screw driven through a wiring harness. My point is if a car with Zero miles can have a Check Engine Light come on then we should all take the light with a grain of salt. I know it unsettling to have it appear.

It is highly unlikely therefore that the oil change caused the light to come on. Could be something as simple as a loose gas cap.

 

sonotech.......working in a dealership for over 30 years, though not a tech......the #1 reason for a check engine light is that the computer sniffed gas......... possibly, gased up and let the engine run???? also Katz will know better, but i think it will reset in time... i think after so many starts.....
am i right with this Katzmans????
rickyd

 

Can take two or three fill ups usually, sometimes three blocks after a fill up and its out.

 

Hello,Thanks for the replies,I took the car to Autozone this morning and had them scan it.The PCM has determined that a malfunction exists in the electrical circuit for the vent control in the evaporative emission control systemDefinition:EVAP (Evaporative Emission System) purge/vent solenoid circuit condition. Explanation:The solenoids and system wiring are monitored for open or shorts.The probable causes are 1.Purge or vent solenoids defective 2.Check connector and wiring 3.Fuel saturated vapor canister 4.Failed EVAP vent solenoid.Ok where do I start to find the problem?All replies will be much appreciated,Thanks

 

Sounds kind of crazy but Reboot and wait for it to return is my advice, it may never. Glad that my long post proved correct though, as I said emissions system causes the light to glow. Rickyd on right track too with that saturated canister message. Gas cap is part of the system so make sure it is on tight too, make it click! Did they turn off the light for you?

 

sonotech, i agree with Katzon the autozone things.....??????...also would reboot. when ineed to reboot, i disconnect the negative ground for about 20 min..... that resets mine........
rickyd

 

Yeah you guys are good,I will try to reboot the car in the morning.I will let you know how it goes.Thanks again

 

Hello,The check engine light is OFF Thanks I rebooted disconnecting the negative on the battery and waiting 20 mins well maybe a little longer half hour.Well the light is off so thanks again.Now washing it this afternoon I noticed a little over spray below the passenger window on the black rubber and on the left rear door below the window same place.Also a faint red looking hair in the paint on the left rear quarter panel.Do you think this car was in an accident,the seller said no accidents I took his word.What do you think?Thanks

 

Maybe the car was touched up for sales purposes. Scraps and dents are a fairly common thing these days, seems like I get a new door ding every time I go to a mall parking lot. PersoanllyI am fussy with my cars and I have a big Suburban, never been in an accident but I have had two doors and the lower rear quarter panel sprayed because of parking lot dents and scraps. Could be lots of reasons for painting a panel or two. I had a Booneville and the rear window wasn't sealed properly from the factory so I had it repaired under warranty, problem was the sealing compound from the factory was squished out on the roof and they had to sand it off and repaint the roof. Sometimes, and the dealers don't like us to know, the cars are damaged in transit or when unloading off the transporters, again the body shop gets involved.