My Chevy 2003 S10 V6 has code P0200 and P0300.. HELP!

http://www.obd-codes.com/p0300 -- this one to. The possible solutions section has some things to check that will help you narrow down what the issue actually is. Hope these help

Thanks for the link....the guy at Autozone said injector 3 was "Open or shorted injector" recommended me to change out just that injector. Is that easy to change out? do i need any "specialized" tools.

How does he know it was #3? To know that for sure it should have thrown a p0203 and p0303 codes.

http://www.obd-codes.com/p0200 -- 1. If you have multiple misfire/injector codes, a good first step is to unplug all the fuel injectors and then turn the ignition on, engine off (KOEO). Check for presence of battery voltage (12 Volts) at one wire of each injector connector. If all are missing, check for continuity to ground on the voltage circuit by using a test light connected to positive battery and probe each voltage feed. If it lights up, then there is a short to ground on the voltage feed causing a short. Get a wiring diagram and repair the short on the voltage feed and reestablish proper battery voltage. (Don't forget to check for a blown fuse and replace as necessary). NOTE: It's possible for one injector to short out the whole battery voltage feed to all the injectors. So if you have lost voltage to all the injectors, replace the blown fuse and plug each injector in, one by one. If the fuse blows, the last injector you plugged in is shorted. Replace it and retest. If only one or two battery feeds are missing, then it's more likely to be a shorted battery voltage feed in the individual injector wiring harness. Inspect and repair as necessary. 2. If you have battery voltage fed to each injector harness, then the next step is to get a noid light to check for injector driver operation. A noid light will insert into the injector harness in place of the fuel injector and flash rapidly when the injector driver operates. Check each fuel injector connector. If the noid light flashes rapidly then suspect the injector. Ohm each fuel injector if you have a resistance specification. If the injector is open or the resistance is higher or lower than the spec, replace the fuel injector. If the injector tests out, the problem is likely an intermittent wiring problem. (Remember that a fuel injector can work properly when cold but go open when hot, or vice versa. So it's best to do these checks when the problem is occurring). Check the wiring harness for any chafing, or the injector connector for loose pins or a broken lock. Repair as necessary and retest. Now, if the noid light doesn't flash, then there's a problem with the driver or the driver circuit. Unplug the PCM connector and ohm the fuel injector driver circuits. Any resistance means there's a problem. Infinite resistance points to an open in the circuit. Find it and repair it, then retest. If you can find no problem with the harness and there is no fuel injector driver operation, then check the PCM powers and grounds. If they are okay, the PCM may be at fault. Read more at: http://www.obd-codes.com/p0200 Copyright © OBD-Codes.com

I feel your 200 code is causing the 300 code. I would check the injectors as described above in order to narrow down your issues. Doing so should give you a better idea of what is wrong and also keep you from just throwing hard earned money and parts at the issue.

niether p0200 or p0300 narrow down cyl #3. Its just injector circuit malfunction and random missfire. The problem with this repair is you have to take the upper intake off to get to the injectors Once done the truck wont be driveable. If you are not familiar with this kind of work I would suggest taking it to a mechanic before you have to add tow fee to your bill

http://www.obd-codes.com/p0200 -- check this out

FYI to this old forum you do not have to take the intake off, just the 2 10 mm head bolts from the injector rail then you can fanigel the injectors out as needed.

You've clearly never worked on a 4.3

When I had this issue it was a failed exhaust valve spring. GM replaced it, gave me the old part, ran like new. I did upgrade my spider injector assembly to a newer version. Changed the cap, rotor, coil, plugs and wires as part of a tune-up. Ran like crap because of the failed exhaust spring.

If you had issues with your old injector set up, you will need to remove the IMUP - Intake Manifold Upper Plenum, which is plastic to access the spider legs < not the technical term.

Ron, i have missfire in number 2 and Injector circuit code, replaced computer, spider injector, plugs wires etc. tested wires for injectors and appear to be fine. Done a compression test and all was above 130. I am stumped and tired of working on this mystery. Anyone have some input??

So im having the same issue with my 2003 s10. Ive put brand new spider injection assembly with new injectors and connections. Where should i go from here.

Im having the same problem with my 2001 S-10 misfiring i do need a new fuel pump I think but this is a different problem maybe all related I dunno.. My engine light comes on and blinks when accelerated..

Has anyone figured this out yet. Distributor maybe?