About 2 months ago, while on a short drive(1mile) my car,2003 P5, lurched forward a little and started shuttering. The RPMs were fluctuating between 800-1500 while stopped at a light. When I parked I left the car on and looked under the hood. My engine was shaking quite noticeably. CEL was on and Autozone said "misfire in 4th cylinder. to lean. bad MAF." Assuming they were right I, not being the smartest person, threw away the print out of the codes and started to fix. I cleaned my MAF and checked fuel injectors coils wires and plugs. Plug 4 had no gap what so ever. Replaced all plugs. Same issues persisted yet shaking lessoned. Was told to check my EGR valve. Cleaned EGR valve and ports in Throttle Body. Cleared codes. Started car and....could still hear the misfire. My acceleration is sluggish. Codes came back but I have not checked them. Currently while driving and stopped at a red light, my car almost stalls out(and has done so several times now). Im not sure if I missed something obvious or what so ANY help is greatful. Also, while at red lights my car is surging with large rpm changes still.

 

Let's look at the #4 plug again and check the compression. To me this all sounds like a mechanical failure. In normal situations the plug gap gets wider as the electrodes burn off. I think something may have hit the plug and closed the gap.

 

Compression was 150,150,145,150. I guess that is within range? I will be checking codes today or tomorrow. Also, I changed out my thermostat and rewelded my exhaust(a weld in my exhaust was completely broken). Next step???

 

The major mechanical things seem to be fine.
I suggest to look for vacuum leaks. There is a ribbed section on the air intake hose (on my '98 protege anyway). That air intake hose is prone to cracking as it ages. Bend and yank on that hose to see any cracks. As the engine moves around it may momentarily open a crack and cause the loping idle.
Any vacuum hose going into the intake could be cracked, chafed or hardened.

How did you check the injectors? You may have used the noid light or listened to them with a stethoscope. These test tell you that they get voltage and move, but they don't tell you if they leak or are clogged.
To that extend I suggest to use Techron fuel system treatment for a few tanks. If you use 87 octane, move up one grade.

 

Codes were P0300,P0304, P0171. I took each injector out and visually inspected it for clogs as I dont have a noid light or a stethoscope. I have also ran 2 tanks with injector cleaner. Gonna stop by a mechanic friends house and borrow some tools to see what I can do next.

 

So after 15 min with a can of brake cleaner, I found vacuum leaks. Hoping this will be it. One of my leaks is the throttle body(either I tightened it too much or my gasket is broken). The other leak is a small vacuum line on the back of my engine(not sure what this is but the line is less than a buck). Fingers crossed.

 

Yes, the P0171 means lean condition bank1, the only bank you have. Once you have the vacuum leaks taken care off. Pull off the battery negative and step on the brakes or push on the horn. That will drain all remaining voltage from the memories and reset the computer.

A mechanic's stethoscope is about $5.00 and the parts store. You could also use a piece of garden hose. I hope you replaced the o-rings before you put the injectors back in.

 

I believe the colloquial name for the garden hose trick is, "Redneck Stethoscope".

 

So I just ordered my fuel injector seal kit (instead of just getting o-rings). I decided this was a good decision after spraying the fuel injectors with carb cleaner and hearing a very small change in two of them. Might as well do it all to eliminate any other possibilities. Runnin better bit by knuckle-busting bit. Almost done I hopme. I now understand why a shop can charge so much, even if they have all the right tools it can take a lot of time.

 

I check engine light came on a couple of weeks ago and i went to autozone to get it checked out and the code came back as misfire on cylinder 1, so i got the parts for it, which was 4 new coil packs and 4 spark plugs, changed those and seen the the coil pack for cylinder one was burnt up and look like it had gotten water in there some how and the spark plug was all rusted up. After i changed all of that the car ran fine for about a week and then the light came back on, engine is idling very rough and when i give it gas to get up to speed it bogs down bad and vibrates. Now the code is saying cylinder misfire 2. What could be my problem. Please helpppppp