so i got a 98 with a 5.2. I keep getting the p0135 heater circut malfunction bank 1 sensor 1. i ve gone through two new sensors. everytime i reset the code i get it back on either in a day or two or three (just when i think its gone). truck hasnt had an issue and runs like it should as far as i know. maybe a little rich which i fifgue is cuz of the o2. Any suggestions

 

Where have you been getting those sensors? If not NTK or dealer parts the first thing to do is get those NTK or dealer parts installed.

That said, 0135 is an odd malfunction and I'd think it time to start checking continuity to ensure that the harness itself isn't foobed.

 

+1 to Unregistered. I went through 3 02 sensors on my 99 2500 before installing an OEM one. Intially I still had problems with the OEM one. Some backchecking of the harness showed it was cut/spliced with a different plug not wired correctly.

 

i found a popped fuse for o2 sensor so im hoping that will take care of it. and its denso o2 sensors

 

Denso sensors are really good and rarely i've heard people having problems with them.