check engine light on ... again

amelia · Post by **amelia** » 27 Jun 2010, 19:09

I have a 1999 v70 T5, with 71,000 miles. I have had continual problems with check engine light being on. I've had it at the dealership many times this past wo years. They have fixed hoses, sensors, gaskets and o-rings. Today, after filling up the car with regular unleaded gas, I pulled in the drive and the check engine light came on. How much money do you put in a car before trading it? I went to Kelly's Blue Book and discovered the car is supposed to have premium unleaded gas. (My late husband had this car and always took care of it). I googled regular vs premium vs check engine light and it seems that regular unleaded gas can cause the check engine light to come on. Can this be true? Could this be my problem? If so, what should I do with a full tank of unleaded regular gas. Thanks for your kindness and help.

zdh · Post by **zdh** » 27 Jun 2010, 19:14

Try tightening the gas cap. If the cap wasn't put on all the way, it can trigger the CEL. If that doesn't work, have the codes read.

Post by **JRL** » 27 Jun 2010, 20:46

The answer is no
Regular gas will not cause a CEL to come on

adk793 · Post by **adk793** » 27 Jun 2010, 21:13

Not directly however regular gas can give some low readings in different parts of the car) and cause some other things to run weird to then cause the check engine light, especially the age of the car.

ajwgator · Post by **ajwgator** » 27 Jun 2010, 23:45

I agree completely with JRL. Regular gas WILL NOT cause a CEL light, directly or indirectly. I have run my 98 V70XC AWD on regular gas from the day I bought it. Go Autozone or some place like that and have them read the code that is causing the CEL and report back here what it is. They will do that for free and you don't have to buy any parts just because they read the codes for you. Just write them down as well as the wording it reports too. As long as your car seems to be running OK it will not hurt to continue running it with a CEL on. It is not an emergency to run to the dealer everytime the CEL comes on. Let us know and we'll help.

Post by **BEJinFbk** » 28 Jun 2010, 00:56

+1 on the gas cap. Turn it until it seals and clicks repeatedly.
And the computers in this car will adjust for any gas with no CEL's.

It may also be worth your time to go mechanic shopping.
Any dealer worth their salt should know ALL the quirks of a '99 by now.
You might check out some of the independent shops in your area. Ask around!

Post by **phils94850** » 28 Jun 2010, 06:41

i had a problem with the evap code coming on and i purchased a new gas cap and that fixed it. You should hear some air escaping when you remove the cap, if not, the cap is bad and not sealing.