I'm going to a shope for a full diagnostics. What is usually checked?

[stevemya76!yaho]

Cause I don't want them to miss anything.

Thanks.

 

[BradE.]

A enhanced scanner will read out a number of different things, can;t really give you a list because it varies depending on the scanner software and the make/model of the car. On average with an enhanced scanner with manu. specific software they should be able to read at least 100 different sensors/values, etc.

 

[Alec]

why are you going to the shop to get this done?

 

[stevemya76!yaho]

I had an OBD II check done, and it gave a code P300 which is

random multiple missfire. But missfire could be mutiple of problems. OBD II coul not tell th exact problem. But I've heard that a full diagnostis will check for most of the problems. Is this true???

 

[Alec]

Hmmm, dunno. Robert or Mrboyle will have to chime in for that one. A random multiple misfire is usually either a computer hiccup, a problem with the coil pack, or plug wires. Have you had your spark plugs and wires changed recently? And how often does this misfire occur (you should be able to feel it)?

 

[stevemya76!yaho]

Spark plugs were replaced 8k miles ago. The car has 68k.
How does missfire feels like?

 

[Alec]

A misfire feels like the engine is stumbling, like it just misses a beat. It usually occurs under some sort of acceleration or under high load cruising.

 

[stevemya76!yaho]

I feel that often. I just hope with diagnostics they'll find the exact problem. I'm going there in the afternoon.

 

[Alec]

my guess is either your spark plug wires aren't seated well or your coil pack is going bad. It could also just be a loose wiring harness between the coilpack and computer.

 

[stevemya76!yaho]

The loose wiring I can check myself. Is there a way to check the coil pack without doing diagnostics?

 

[Robert]

When I got my P0300 a couple of months ago, it was because my MAF sensor had popped out of my intake tube. I had put my K&N FIPK back on a couple of weeks earlier and must have forgotten to tighten the hose clamp. My MAF was sitting at about a 45 degree angle to my intake hose. The first time the code got set, I was coasting down a mountain grade. I pulled into the first gas station I found when I got into town. I ran my codes and had the P0300. Five out of my six cylinders had recorded a mis-fire. Wasn't really sure what was up with that, so I cleared the codes and when on my way. I wasn't 1/2 mile back on the road and the light came on again. I cleared it again and drove a little further and the light came on again. This time I stopped and removed my SuperChip since I have had flaky things happen before with it in. The light didn't come back on the rest of the day so I though that it might have been it. During the day I noticed a clanking sound from under my hood that was driving me nuts. I pulled over again and that was when I found my FIPK loose and bouncing against my hood. I tightened everything up and put the SuperChip back in and haven't seen the code since.

I really doubt that any kind of "generic complete diagnostics" will find the source of your code. It will only be a snapshot of your sensors at one particular instance. You need to have your vehicle diagnosed by someone looking for the source of the P0300 code. Just look over the obvious things first though like spark plugs, wires, air leaks.

 

[stevemya76!yaho]

thanks