ladydi

My daughter's 2007 2.4 HHR's check engine light comes on for a couple days then turns itself off for a day or two then comes back on. It's not a flashing light so I know it is telling me there is a problem. I took it to my mechanic and he suggested I take it to a dealer because it has a slight (not really noticable) miss in cylinder #1. Went to dealer to have it scanned. Came up with codes P1174 and P0300. Found TBS#03-06-04-03H. TBS used AFIT Fuel Injector tester and tested injectors. #1 failed so I know I need to replace #1. He added 44-K Fuel System Cleaner to fuel to see if it would help the injector to clean out. The light was off when I had it tested and drove it back home. The light is now on again and my main concern is it okay to drive it with the light on? (my daughter works 30 miles away, mostly freeway) or should I not have her drive it until we can have the injector changed. Also if I am having one changed should I change the rest. I'm not made of money so this will have to wait until next week when we get paid.

LawDog88

I would do all of them at once. Being a 6 year old car, it could be only a matter of time before the rest need changed. So if you are in there getting it done, do them all is my thought.

donbrew

You folks that think 30 miles is a huge commute!

If it is positive/for sure the injector and it's been going on for a while, let it go until you can fix it. Knowing that certain things may be disabled because of a CEL, like cruise control shifting may be "hard", etc.

However, you'd be smart to switch a couple of injectors to see if you get a different P03xx. P0300 means random, P0301 means #1, P0302 means #2 etc.

44-K will take time to work.

ladydi

Thank you LawDog88 and donbrew for the speedy replies. I have decided to let my daughter drive her car to work and back so it will give the 44-K time to work. I was only worried that it might hurt the car in some way. In fact my daughter got in the car to drive it into the garage and she said the light was out. Go figure. If we continue to have problems after the fuel additive we'll take it in and switch the injectors to make sure and if so have the injector (possibly all) changed.