In the process of getting my car legal to pass inspection, and i've got it down to two codes.

both upstream o2 sensors are coming up with a "slow response" code. These are brand new Bosch sensors i installed with my new system. I have brand new bosch downstreams as well and they're not acting up.

Any ideas? I still have the old AC delco sensors from my old system, but they're stock sensors. Should i attempt to switch them out and see what happens?

And please don't just say "go get ac delco sensors"...

 

The general concensus is that people have the best luck with AC Delco O2 sensors; your problem could be the Bosch parts.

 

.....

Any idea what the code means? How can an o2 sensor have a slow response?

 

"Healthy" O2 sensor voltage output will bounce back and forth from approximately 100 mV to 900 mV about 10 times a second once they are warmed up. Slow response means they're not moving.