I just got a 88 k5 with a 305 tbi and it had been sittin for awhile but the engine and tranny only have 16,000 since rebuild the fuel pump was out so i replaced that and fuel and air filter, plugs and wires, and starter. It still has the factory cat on and i think it could be clogged and causing problems. I have no power going up hill not alot of acceleration and using alot of gas. Could it just be the exhaust? It runs great at idle but not under a load.

 

Definitely a possibility. I would disconnect the O2 sensor and remove it from the exhaust. Then drive it. It will be loud, but if the bog is gone, it is a sign of a failed catalytic converter. By removing the O2 sensor, you give the exhaust an exit before the cat, relieving pressure that would build up due to a restricted catalytic converter.

 

Thanks that is alot better than payin $230.00for a new cat i might not even need.I will try without the sensor in. Ireplaced the 02 sensor but someone said that there are 2 oxygen sensors is that true? Also i was wondering if having a 305 in there when it originally hada 350 would cause this. Would the computer still be putting in enough fuel for the original 350? It is running rich and its not the pump and the regulator looks fine. Sometimes you cant hardly give it any gas because it sputters and chokes and accelerates very slowly and uses ALOT of gas and the engine light will come on and then go off in a minute.Sometimes if you floor it and it chokes it will die.I havent reconnected the hose under the filler neck hose( vent hose? )from when i dropped the tank would that affect anything? is there another sensor that would do this?Someone said something about a rich oxygen sensor?

Thanks

 

Check for any stored codes in the computer.
The fuel requred for the 305 would be the same as the 350.
Connect any hoses that you have disconnected.
My '90 was bogging recently because the fuel pump was weak.

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