2002 Chevrolet Tahoe Service Engine Light Blinking?

If the light is only blinking, then it's a very temporary incident and no worry,.

I would assume that if you didn't have the tow package installed ,it might be a temporary water temp sensor affecting the signal to the PCM, whereas at time you may not be getting the full required fuel flow, and a possible bad air fuel mixture.

A common problem for emissions is the EGR valve. They aren't always bad, but they will get blocked with deposits preventing them from opening or closing completely when required. This problem will also cause lower gas mileage and a rough running engine. It can be removed and cleaned if it is still good. A bad or weak O2 sensor can cause the PCM to make a wrong fuel ratio adjustment and effect fuel economy. This could cause a fuel system related DTC to set.

Have a 1997 suburban it do e the same thing and had goodyear mechanics stumped. Ended up having a blown lower intake gasket. It would act fine if accelerating but when maintaining speed it would miss and trip the check engine light for misfires. Spray around the intake with starting fluid while vehicle is running and see if it changes the engines idle.

A flashing CE light indicates a miss fire condition, miss fire under heavy load is usually ignition related but you seem to have checked that out already but I have two questions: were the plugs replaced with the exact factory AC Delco Plug recommended by GM? If not I would install factory plugs before trying anything else! Second were the coils tested at maximum load? I have seen them fail under load with no symptoms apparent during routine analysis.

Other possible causes include low fuel pressure and excess back pressure from an exhaust restriction or plugged Catalytic converter.

plenum gasket......or whats causes that alot to on them chevys is a catalytic converter on its way of plugging up. That can cause them symptoms. A compression test is always nice to cuz then u beable to tell if its in ur tahoe cylinder heads or not to. But my money is on catalytic convert. Have the exhaust checked, compression check, and intake gaskets checked. Hope that helps

Check the module, your coil packs plug into it. Most misfires that are not due to plugs or wires arching/bad and not routed wrong, can be caused by either the coil packs, module or the crank sensor... or even injecters if I'm not mistaken your tahoe should have independent coils for each cyclinder, you might also want to try some techron by chevron fuel treatment.

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