Trouble codes

I have the same codes after changing my spark plugs. I cant reset the light or make it go out. I put the old plugs back in and still have the light. I cant identify the code other than mis fire or ignition module. I cant find the code id or any repair info as yet.

If you have code 1311, and the scanner says that it's a random missfire, check your spark plugs,this code refers to "ionization" and this means reverse polariztion at the time of the comustion (burnig) of the fuel and air mixture in the cylinder chamber. Check and see if you have individual coils going to the spark plugs and check and see if any wire is disconected (you ares supposed to have 3), also check if you have the right spark plugs installed, this code is found in most vehicles since 1999 and what it does is checks the combustion in the cylinder and since there's some electricity produced at the time of combustion the spark plug doubles as a sensor, then it sends a signal to the compurer, so your problem shoud be in the coil and spark plug wiring (primary). If you have a trooper, then you have some very short wires inside and under the coils. Also if you changed the timing belt, check and see if it es correctly installed. use a timing diagram.

Yes, it is troubling having these code coz the OBDll Reader will show you a generic code which I also faced.. Misfires mean vacuum leaks, fuel injector's problem, lower fuel pressure, weak ignition coil, bad plug wires, compression problem and dirty MAF sensor. Check intake vacuum gauge if needle is jumping up and down(17 to 21) and its hose and connections, and the throttle body, manifold and PVC valve; check fuel pump coz it may have a low voltage, its relays and wirings;check for possible obstruction on the fuel line like plug and filter; also, you may have a bad fuel pressure relay to the injector(dirty injector). Check if you have a clean EGR valve coz it might have accumulated carbon, and, PVC valve,too.

I have had fuel pump replaced flow lines cleaned and still occasionally it will die just going down road and it would not start after it happened 2 times and the work was done.it was running fine abd did the same thing again but started after several tries.had tested at auto zone and code 452 showed which they said was a fuel tank pressure sensor.any help on where this part is located or is it involved with the fuel pump?thanks reba

I took my trooper to a reputable transmission mechanic because my "check transmission" lite keep coming on and I would have to either turn the car off to reset the sensor lite or drop it down into 2 gear and than back up to drive (it's an automatic tranny). They put my trooper on the diagnostic machine and came back to tell me that "error code 429" keep coming on. They contacted an Isuzu mechanic and he said that "error code 429" meant that my alternator was throwing out too much voltage and was kicking my transmission down. The transmission mechanic suggested that I get an new alternator but I'm not sure about this. Can a alternator cause my transmission to kick down into low? I have a 1993 Isuzu Trooper with 135,000 miles on it, it's a V-6 and I'm not sure the engine size, I've only had it a couple of weeks. Thanks for any help on this.
Janet