2000 K3500 running rich issue HELP

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08-23-2010, 10:05 PM

soldier05354

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Join Date: Aug 2010

Location: Vergennes, VT

Posts: 1

2000 K3500 running rich issue HELP

I went to a used car dealer in search of a new one to pickup to haul campers with. They had a 2000 Chevy K3500 LS Dually 4x4 full size crew cab for sale. This truck was perfect for what I wanted it for because it already had the fifth wheel tow hitch in it and a vortec 454 engine. I got the keys from the dealer to hear it run. It started fine no service engine light. The exhaust was loud. I got on the ground and looked. No cats chopped out and dual straight piped to a dual in and out magnaflow muffler. Under the hood I saw a Airraid cold air intake and a throttle boddy spacer. Had a fog horn on the roof too. I took it for a test drive. Surged at stop light. Easy fix I figured TPS I thought. So I bought the truck. I put a new TPS in because the old one had no spring left in it and a lot of play. Truck idled fine now but now service engine light came on. Rich on bank two some times it shows on bank one but not always. Bank two throws every day. Researched exhaust system at chevy dealer. Supposed to have four 02 sensors in it. Truck doesn’t throw codes for the two that are missing that are supposed to be behind the cats. Two in headers still ther. Also wiring for thos 02 sensors is no wheres to be found. I replaced the MAF MAP CAP ROTOR WIRES PLUGS FRONT THERMOSTATEBANK 2 O2 SENSOR. None of this helped. I pulled the plenum and took out the fuel injectors. Some one didn’t know how to push the metal clip on the wire to release it from fuel injector. Plug still works just doesn’t clip onto the fuel injector any more. Truck runs rich throws codes but I still record 18.9 MPG yeah 18.9 MPG unbolivable. Truck starts fine cold but flods hot. Have to step on gas pedal to unfold engine when hot. Runs fine hauls like nothing is behind it. Fuel injectors were after market bosch. Left those in and just replaced o rings and fuel pressure reg. new plenum gasket. Still runs rich and throwing codes still. Pluss missing 02 sensors don’t throw codes. Actron scanner doesn’t even see them either like they never where ther. Chevy says they should be there but cant explain why they don’t throw codes. Why am I running rich and why are the two after cat 02 sensors not throwing codes or even show up on a scanner when they should be in the truck.