sonomacrew01

In a quest to resolve a rich running engine (failed emissions), I'm looking at a couple items before bringing the car to a tuner. Figured I'd start with the O2 sensors.

Drivers side on the left, passengers side on the right, notice the carbon deposits on the drivers side as opposed to the passengers side.

coupeguy2001

I would start with ohming the injectors. if you have a bad one, it may cause the rich problem. check each plug for deposits like what appears on the O2 sensor.
The Sensor on the left is heated, and the one on the right isn't.
I would lean more to an injector than the sensors.
But it's always possible the sensors are going south given the environment they live in.
also, it's possible you have a manifold leak or other vacuum leak on the right side causing the O2 sensor to call for more fuel, and the left side just doesn't require the extra fuel to keep from doing a lean burn. but it's also possible the left bank has a bad injector..........

NocarbutaVetteforme

Just a quick question. How many miles on this set of injectors. If they have alot of miles on them, that wouldn't be too bad. As they go bad and get clogged, it would seem like they would act like regenerative feedback. I think the main thing is the number of miles on these injectors to properly diagnose if there is a problem.

sonomacrew01

so the sensor on the left is heated and the one on the right isn't? Could this be the potential problem? 93 shouldn't have heated O2 sensors.

I'm assuming the injectors are original and if so, there's 81,000 on them but last year I had them sent out to be cleaned and tested...

mseven

what helps me understand if a 02 is getting trashed is by looking at the 02 Mv and cross counts in a scan. When I have had them go south, cross counts are slow and voltages stay almost fixed around.800 Mv.

RRT vette

The O2 sensors look different in the pic. A stock O2 sensor will have one wire (purple) and a heated O2 sensor will have 3 wires. Not the best idea to run different O2 sensors but it shouldn't matter as long as the heated on is not connected to 12v or a ground. If it is, then the heated O2 sensor will start sending signal to the ECM for closed loop before the other sensor does.

sonomacrew01

I did some research on O2 sensors for the 93. The one on the left is AC Delco and right is Bosch (I believe). Both are non heated.