gaspergou

Started getting code P1133 today. Aside from really crappy fuel mileage, will it cause any harm to engine if I drive it like that for a couple of days?

donbrew

P1133 CHEVROLET HO2S Insufficient Switching Bank 1 Sensor 1 | AutoCodes

It could be a vacuum leak. Or a wiring problem.

A few miles should be OK. But more will kill the catalytic converter.

Oldblue

Yup, check it out ASAP, before you damage the cat!

gaspergou

Dealership should have new sensor tomorrow. Hopefully I can pick up the part and change it tomorrow afternoon. Thanks for the input.

gaspergou

30 miles to drive home from work. Hope that's not too much.

donbrew

A. Why pay GM price?
B. It might not be the sensor! Read the link I posted in post #2 or GoOgle "p1133" and read any link of your choice.

More often it is caused by the wire falling onto the exhaust and melting.

gaspergou

Thanks donbrew. I did read your link above. Wires all looked good. As for GM price, I rarely use the dealer for parts. This time its just peace of mind. I read a few articles about people having issues with some aftermarket sensors. After over 236000 miles it deserves a little home cooking.

gaspergou

Also curious how will I know the new sensor is working? Will the check engine light go out on its own? Do I need to reset check engine light by disconnecting battery? Or will I just know because the mileage is back to normal? The car runs smooth, so I won't notice anything from the idle.

donbrew

It should go off by itself may take a couple of cycles.

Don't be surprised when you see the Japanese brand on the dealer part. The ones to avoid are Bosch.

gaspergou

Well things seem to be back in working order. Old part out, new part in and no engine codes(yet). Price of new part at dealer about $79 plus tax. I'll feel better after about a week or so. Thanks to everyone for advice and tips.