My car has a shaking problem at highway speeds (55+). When it starts to shake, it generally stops after a few seconds followed by a service engine light. A shop told me that the code was for my O2 sensor, that i should look into getting it replaced. The light comes off and on, and the shaking is never consistent. It could shake while going up hill, down hill, accelerating, or decelerating. It has recently had a lot of work done to it: new distributor and cap, plugs, wires are good, oil change, alternator and new battery. I went and recently replaced most of the fuses. Ive heard some possible causes are the O2 sensor, the fuel filter, and possibly even the fuel pump. Any suggestions that could help me figure it out without wasting any money in the process?

 

Start with the cheapest, by replacing the fuel filter.

 

How about some troublecodes? Its easier to pinpoint a problem if we had a troublecode.

 

The shop didnt give me the actual code number unfortunately... all they said was it was indicating a bad O2 sensor. I couldn't pull those codes myself because the ALDL connector was apparently moved? When i pulled the face plate off where the cigarette lighter is, there was something different sitting in there. Either way, I drove the car a bit of a distance a few days ago, about 30-45 minute drive one way. Kind of ran rough as I described... well now on my way to work it never shakes. I still get the check engine light after hitting high speeds, and theres still an obvious loss of acceleration. And something else I didn't mention apparently is there is a noise that sounds like something electrical running the whole time the car is running. Sounds like the noise you hear when you turn the ignition (kind of like how some cars sound when maybe their attenna extends out). This all started after I had sthe battery/alternator replaced... after I replaced the battery my radio went out, the engine made a strange noise and was revving nearly 2500 rpms in park. Turned it off and restarted it and ran it for a few days, then this started to happen after I then had to replace the alternator. I haven't taken action on anything yet, as I am trying to save my money for my Firebirds engine rebuild.

 

sounds like a filter to me. was the light flashing randomly, sporatically? no codes are stored for a bad filter, but the light will flash when the car stumbles

 

yea, the light doesnt stay on. it will come on and go off whenever it pleases pretty much, and not always with some kind of noticeable symptoms. Personally feel the car is running a little warmer than it should be. as long as i never go above 45 to 50 mph, the light will never come on, and also never comes on until the temperature gauge reaches normal operating temperature.

 

Sorry to say this Jaysome, but I believe you basically handed the mechanic money for nothing. I'm a PC tech. If a customer told me that the PC freezes a lot and that he wants a diagnosis, i would say it costs $50 for inspection. I can easily tell the customer that there is a problem with the software and charge him $50 WITHOUT even turning on the PC. I think thats what the mechanic did.

 

Why do I think that? because there is no way to say that the O2 sensor is acting up without connecting a computer to the ALDL if its not there.