Have a 1996 gmc savana 3500 replaced the oxygen sensor because it had started pinging a little. New sensor made it start knocking bad, put the old one back in and it went back to pinging, wrong sensor ,any thoughts

 

what grade fuel are you using? try using a higher octane fuel.

 

So the truck should have 4 o2 sensors, did you replace all of them?Or at least the 2 upstream. Regardless it is most likely not the problem. Is the check engine light on? What is the code?

 

No check engine lite, but there is only one sensor

 

Look again and closer. There is always 2 sensors for each bank. A pre catalytic and one after the catalytic converter. Maybe someone has made some changes over the years.

 

Probably not your o2 sensor. An inoperative EGR valve will cause light pinging. No exhaust gas recirculation will raise combustion temperatures to the point of light pinging. Chevy dropped the EGR valve on some later vehicles but I believe yours has one. Usually the back pressure valve in the EGR gets plugged and prevents the valve from opening.

 

Thanks for the info, I will look into that. Tried to drive truck today and it acted just fine until it got up to operating temp then started to nknock again
jim

 

Strange. The engine has a knock sensor to retard timing which prevents pinging before your ear ever hears it. If it's working right, no ping. If it's not, you should get an error code.
I'd scan the truck just for fun, wouldn't be the first time someone had a stored code without the SES light being on. AutoZone will do it for free.

 

Good point thanks

 

i have a 1996 chevy 1500 5.7 vortec and i its not running right i have replaced the fuel filter, fuel pump delfi pump, it jumps when i go to take off its definately an electrical problem but cannot figure out what it could be put new plugs and wires in it and still nothing if anyone has any tips or has had this happen to them it would be great for any ideas or help, new to this site gonna give it a try thanks