1985 GMC Jimmy V8 oxygen sensor

[clarissa]

Hi,
Just stumbled here. I need to replace my oxygen sensor and am having trouble locating where the old one is. I see something like it underneath the spark plugs but not sure if this is the temperature sensor. Anyone know?
TIA

[1974ChevyC10]

what kind of motor do you have?on the 80's 305 motors that had ESC they had a large object in the center of the side of the block-i dont recall what side but that is the knock sensor for the motor.you may also be looking at the sending unit for the temp gauge i believe they couple be threaded into either head but i could be wrong there-thats hard to say w/o being there or seeing a pic-do you have a pic of what you saw-that could help.to answer you question regarding the oxygen sensor its in the exhaust pipe most likely before the catalytic convertor.i may be wrong there too-hopefully someone with an o2 sensor equipped truck will chime in as mine doesnt have one.

[clarissa]

Thank you. It's a 5 liter (302) 4WD. The book I have covers the V6, mine's a V8.

[RockHQ]

It'd be a 305 cid engine, really. Ford has the 302 that's referred as being a 5 litre engine most often. Chevy made a 302 i believe for the 67-69 Camaros which is extremely rare and desirable. A 305 from a C-10 most likely would not have an oxygen sensor if the engine is original to the truck along with it's ignition/fuel/emissions systems, since it should be a carbureted (4-barrel Quadrajet) low emissions engine with an Electronic Spark Control computer (knock timing retard system).

[SanitysBane]

rockHQ ur right on the chevy 302, came on the cameros, was a factory drag car, had a solid lifter cam in it from the factory. anways, i don't belive that anything that has a carburator would have an oxygen sensor unless someone put one in to tune the carb with.

[KShortell]

Only California-emissions trucks had oxygen sensors for the computer-controlled carbs. If this is what you've got, it should be in the exhaust pipe between the exhaust manifold and the catalytic converter.

Good luck!

[Grim Reaper]

Originally Posted by KShortell

Only California-emissions trucks had oxygen sensors for the computer-controlled carbs. If this is what you've got, it should be in the exhaust pipe between the exhaust manifold and the catalytic converter.

Good luck!

Yep only cali and that's on the CCC (Computer controled Carbs). Trucks didn't get FI till 87.

Honestly if your having problems and not in Cali or a real hard core emmeions area where they pull the car apart and look for CARB numbers I would ditch the CCC and get a Electric choke Quad and a regular HEI.

Also your truck probably has ESC ignition. Again if it gives you problems...scrap and go to HEI.