I recently did the paper clip trick with the obd and got the code #43 i looked it up and found that it was knock sensor error what exactly does this mean i thought that my truck didnt have this it is a 94 chevy 1500 pick-up is this possible? I dont havce the o2 hooked up and i didnt get that message could it be possible that my computer gave me the wrong message. The truck runs but as soon as i take my foot off the pedal it shuts off it stumles alot. I am running rich because my plugs are black. I went up on the cam when i did the rebuild and it has 192/203 duration so i am good there it builds good oil pressure and sometimes it runs hotr and sometimes it doesnt i mean i  have been at this for a ovr 2 years now and time is getting short i am planning on taking it to the local muffler shop and have a 02 bong welded in and i am wondering if a custom chip would do me any good  any insight would greatly be appreciated.  

are you trying to run factory fuel injection with out an o2 sensor???    get the bung installed.. and hook the new 0 2 sensor...     now you really did not say what kind of injection system.. if it is vortec.. you have also have a bad pressure regulator.. DORMAN has them so you dont have to buy an entire spider...



and it runs hot sometimes???? did you install a proper 195 thermostat????

lack of a thermostat will not let the coolant to slow down enough in the radiator to cool off...  so it will take a long time to get hot.. and on warmer days it will get hotter and hotter till it overheats... also becasue fo the lack of restriction the stat causes the heater core will usually not get proper heat...

there are charts available for every trouble code.. i dont have the book for that code infront of me right now...  and is it tbi or vortec if there is two differnt engine that year....  

I am sorry my frustration got the best of me. It is a tbi system and my o2 sensor is not hooked up i ran it like tjis before and believe it or not it ran pretty well. I purchased a bigger tbi from a shop it is 46mm. It has a 195 thermostat and 2 14inch electric fans. its got good open throttle but idle is ruff i thought it was a vaccumm leak but i didnt find a leak. Do you have any idea if this engine is supposed to have a knock sensor? thanx in advance  

just because it worked well with an oxygen sensor disconnected with the orignal fuel injectors is amazing... now you have installed differnt bigger injectors and a larger throttle body.. and you have blinded the computer from being able to correct for these changes.,. and you still expect it to run good.....


the entire feedback system is dependant on the oxygen sensor readings/./.........  wide open throttle and heavy loading is preset in the programming...  everything else is changable... and can be recalculated by the oxygen sensor feedback to the ecm.....................


since you are so up set with your ... what ever year what ever make,,, what ever model..  what ever engine size... i am going to be upset as i dont know enough to give you an answer. .......


oh.,..... 14 inch electric fans...... are they blowing the right direction...??????    are they blowing hard enough to get rid of the btu's you engine is creating????     are they strong enough.????  do they have enough power to them or just some 20 gauge speeker wire?????

the end...........  

Ok here is my set up its a 94 chevy 1500 pick-up with a 350 bored 30 over, it has new rods, pistons, and i had a 3 angle valve job done on the heads, it has a billet hei distributor with a MSD coil and MSD 8.5mm wires, the cam is a mellings 22101 280/295 and @.50 its 192/203 with 420/443 center at 107/117, with heddman hedders and dual exhaust 3 inch all the way back with a set of 3:73 gears out back the fans are pulling and yes they have enough juice as i ran them with heavy gauge electrical wire (not speaker) with the heavy duty relays to match.It has a super chip in it now that was burned before the new motor. the injectors are still stock but with the new throttle body they are feeding it pretty good as i am getting black plugs out of the block  

If you had a bad knock sensor it would cause your engine to detonate. I'm amazed you havent had a O2 sensor this whole time. Install the O2 sensor,  get the system back to how it was designed then go from there. Without a complete system.........  

94 95 tbi shows a dark blue wire to the knock sensor in the right side of the engine block...  from a 4 pin module on the firewall above the right rocker cover..

the oxygen sensor is a purple wire coming off of ecm D7.. if you have to trace it back...


like i said above... it needs the oxygen sensor to reset the fuel mixture...  the computer really cannot tell how much fuel it is spraying...  

Yes, the motor will run pig rich without the O2 sensor connected.

The knock sensor just screws into the side of the block, so it's pretty easy to change.