P0138 code on a 1998 jeep Grand Cherokee


#1

Hello all,

I drive a 1998 Jeep Grand Cherokee, 6 cylinder engine, with about 120,000 miles on it. I used a code scanner and pulled a P0138 code-bank 1 sensor 2 O2 sensor high voltage, if I’m correct. First of all, it looks like this sensor is after the catalytic converter, right? So I think I either have a bad 02 sensor or a bad catalytic converter. Praying to Chrysler it’s the former, what are the consequences of driving around without fixing this? Will I see any reduction in fuel economy, or any potential long-term problems elsewhere?

Also, if any of my assumptions were wrong, please correct me! Thanks!


#2

Bank 1 would be cylinders 1-3 and sensor 2 would be the post catalytic converter sensor. It’s likely it’s just a bad sensor. The only thing it will hurt to run the vehicle with the bad 02 sensor is that the CEL will be on. All the post converter sensor does is confirms the catalytic converter is doing it’s job properly. The pre catalytic converter sensors are the ones that assist in controlling fuel economy. If you want to put a new sensor in to get rid of the CEL check eBay, I recently bought a new 02 sensor for my son’s '02 Escort there for $18. instead of the $60.-$80. price tag usually associated with an auto parts store.


#3

Thanks FordMan. I’ll put in a new sensor, but it’s good to know it’s not a critical issue. I’ve checked eBay briefly-was the sensor you bought specific to Escorts, or did you get a universal sensor?