CEL light on 99 rodeo

my wifes 99 rodeo gets a CEL light in the fall and winter only. was wondering if anyone else has this problem. eventually gonna take it to autozone and get the codes pulled but was just curious if anyone has ran into this before.

thanks,
Hangman

my wifes 99 rodeo gets a CEL light in the fall and winter only. was wondering if anyone else has this problem. eventually gonna take it to autozone and get the codes pulled but was just curious if anyone has ran into this before.

thanks,
Hangman
Could be an O2 Sensor Heater Circuit Failure. It shouldn't affect performance, just the time it takes for the O2 Sensor to reach operating temp. Not real sure how the circuit works but it's possible that in SC in the spring/summer it's warm enough that the sensor doesn't require the heater so you don't get the code. :2cents:

Could be one of hundreds of OBDII code possibilities. Most common are EVAP system codes (due to loose gas cap) or EGR related. If your local autozone does not read OBDII codes, the $39 code reader from harbor freight tools works like a champ.
G/luck
Joel

Could be an O2 Sensor Heater Circuit Failure. It shouldn't affect performance, just the time it takes for the O2 Sensor to reach operating temp. Not real sure how the circuit works but it's possible that in SC in the spring/summer it's warm enough that the sensor doesn't require the heater so you don't get the code. :2cents:


is that circuit "in" the O2? so that if i got new O2's for it that circuit would be replaced..or is it somewhere else?

thanks

is that circuit "in" the O2? so that if i got new O2's for it that circuit would be replaced..or is it somewhere else?

thanks
You can throw parts at a CEL all day long but until you get the code read... :banghead:

is that circuit "in" the O2? so that if i got new O2's for it that circuit would be replaced..or is it somewhere else?

thanks

Yes on heated oxygen sensors like most vehicles have today, the heater element is built into the sensor. The make them 'heated' nowadays so they go to work faster instead of waiting for the truck to warm up. The element is like a light bulb, once she blows, the heater circuit opens up and the OBDII system triggers the CEL. You have 4 oxygen sensors on your truck at about $50-60 each. Don't replace any of them unless you have a specific code that says you should.

G/luck
Joel

got the codes read last night, it came back with 3 codes...

1 ) throttle position sensor
2 ) O2 sensor heating bank 1 position 1 (which side is bank 1 on these)
3 ) random O2 bank 1 position 1


tps.... no biggie
O2.....$100.00



hmmmm wonder if insurance covers fire??????(j/k)

got the codes read last night, it came back with 3 codes...

1 ) throttle position sensor
2 ) O2 sensor heating bank 1 position 1 (which side is bank 1 on these)
3 ) random O2 bank 1 position 1


tps.... no biggie
O2.....$100.00



hmmmm wonder if insurance covers fire??????(j/k)
Bank 1 is the passenger's side. Sensor 1 is before the catalytic converter.

You should be able to get an O2 sensor for ~$50 and with a 22mm wrench or O2 sensor socket change it yourself.