It doesn't matter if you are the original owner or not, it is still covered. Warranty on emissions for 2003 year cars is 8 years from delivery or 80,000 miles. My Vette, a 2003 Z06 just had one of the catalytic converters replaced under warranty. The O2 sensors are covered under warranty. This falls into the category of take it to the dealer which may not be a bad idea. You need a scan tool to monitor the individual voltages to know which is bad. There is no way to tell which sensor is bad by the code. 75 volts, if nothing happens then the O2 sensor is bad, bank #1 O2 is on the same side as #1 cylinderĬheck the connections to the four O2 sensors first to make certain they are not corroded. You will need to check the output signal from this O2 sensor, if the voltage low (.10-.25 volts) try spraying propane into the air cleaner to see if the O2 volts go up, it should go to around. P1133 - Heated Oxygen Sensor (HO2S) Insufficient Switching Bank 1 Sensor This operation is illegal and you are lucky the dealership did not report you.if this is a registered for road use. Many of these vehicles have had O2 wiring issues driver side ,very hard to access this side. Swap the driver side O2 with the passenger side see if the code moves if so it is just the O2 sensor. Any suggestions as to what is causing this? Many thanks.īank 1 sensor 1 O2 sensor is up stream of the cats driveside,you having no cats leads me to believe that the driver side O2 sensor is damaged.or the connections to it are. Only problem is I have none, and Nelson Performance adjusted the tune accordingly. What does this mean exactly? Ive checked the other threads related to this, and I noticed the cats were mentioned. I've checked the Haines manual and it states that it is 'Oxygen sensor insufficient switching (pre-converter sensor, left bank). I drive an '03 with a 4.8, and after a huge fiasco with the dealership, and swapping and cleaning MAFs, my truck is throwing the P1133 code.

P1133 engine code