After repairing my leaking flex pipe, my engine is still running rough. It is not in limp mode, and accelerates fairly well but it sounds kind of like the old Volkswagen motors. I tried to upload a video with the engine sound but couldn't.

The codes I get are generally pending codes-171, 302, and 300 though I did get a P1174 current code once.

I replaced the spark plugs with an old set I had but it did not help. I also put in Techron fuel injector cleaner to 2 tanks of gas but that didn't help either

I am thinking either coil pack or injector. What do you think?

Thanks again for your insight and wisdom

 

A good, free diagnostic technique for a misfire like this - your misfire is on #2, so swap spark plugs #2 and #4, and swap coil packs #2 and #3. If the code changes to P0304, then it's the spark plug that is bad. If it changes to P0303, then the it's the coil pack that's bad. If it stays P0302, then it's something mechanical in the cylinder (rings, valves) or it's the injector. You'd then perform a compression test to see if it's mechanical.

 

The problem is the only code I usually get is the 171. I have only gotten the other codes occasionally

 

Possibly dirty MAF , dirty throttle body and or dirty fuel injectors.

 

Thanks I did remove the MAF and sprayed the cleaner on it a few weeks ago but it didn't help
How do you clean the throttle body?

 

Remove the four bolts, spray both sides, do not move the throttle plate, the plastic gears strip very easily

 

That is not a reason to not try the swap test. The misfires could cause the car to think it's rich, and as a result long-term trim lean. The it will be too lean on startup and could trigger the P0171. You also should run the car with a scanner on it and see what the a/f and trims are doing, long & short term.

 

It could also be low fuel pump pressure.

 

Runs rough at idle and ok on the road?
Is so clean the TB for the idle problem and for the lean problem look at fuel pressure.

 

Hello again Been busy with other projects but need to solve the code because it is inspection time.

I switched coil packs,cleaned the MAF again, and still get the 302 code. (But I only get that code occasionally.) I always get the 107 code. My engine vacuum is 21, so I do not think I have any leaks.

Guessing it is the injectors. From what I read, it is an easy job. Pull the 2 fuel pump fuses, crank the motor to relieve the pressure, remove the 2 bolts holding the fuel rail, then swap the injectors. Is that all there is too it?

Also, there are many too choose from, with a wide difference in prices. Which are the best?

Thanks again for all the help and guidance