My1997 Ford F150 truck's check engine light has come back on after having new wires, plugs, etc., I put a bottle of Heet in it and was done to about 1/4 tank of gas and the check engine light come on and it sometimes flashes. I had it checked out and the mechanic said it read plug #6 but he pulled that plug and said nothing was wrong with it and reset the light. It stayed off for about a block and is back on. Could it be an O2 sensor or a bad gas cap??? I would really appreciate any help, I have to take it on a trip this week and am afraid I might harm engine if I drive it like it is. Thanks again.

 

What is the exact numeric code? You can get the codes read free at most auto parts stores. Which engine do you have?

 

What kinda plugs and wires you use?

 

I am not sure of the engine and not quite sure of what type of plugs ans wires were used, I know I asked for middle of the road... they were pretty good quality. The tune up was done a year ago. Like I said it didn't start until I put a bottle of Heet in it and then about 1/4 tank of gas left it started to miss and the light came on. Sometimes it will stay on and then it will flash. It doesn't always seem to be missing always either. The place I took it to charged me $40.00 just to tell me it read plug 6 but like I said they pulled the plug and said nothing was wrong with it. Sadly, I have to take it to the shop because my dad just passed away.. otherwise we could do the work. I just want some ideas before I take it in so I don't get ripped off. I do know a little about cars but in this town if they see a female coming you could have bought a new one. Well I will check on the engine.plugs, and wires and get back to you guys. Thanks for your help, it is greatly appreciated.

p.s. No such luck it could be a gas cap???

 

The gas cap loose would give you an emission code. Not a miss fire code. Once you get the check engine light code read, we should be able to help you from there..
Sorry to either about your father

 

As I said, you can get the codes read FREE at most auto parts stores, except in California and Canada. Autozone, Advance, and O'Reilly all do it as a free service.

If it's a 97 and it uses spark plug wires, it's either a 4.2 V-6 or a 4.6 V-8. If you open the hood and look at the plastic cover on top of the engine, it should say what it is. If the cover is missing, look at the emissions sticker, it will also say. If that's missing too, count the spark plug wires, there will be either 6 or 8, half on one side and half on the other.

 

Hello,
Thanks for all of your responses, I ended up taking it in to the shop and the first time there was coolant that leaked into plug 5&6 so he tightened the coolant hose and said he had to replace the plug wires because they had been damaged from the coolant (they were less than 1/2 yrs. old), so I had it a day and the light came on again and I brought it back in and the 2nd time he said it was an 02 sensor so that was replaced. So far the check engine light is staying off Once again, thanks for all of your posts.