I have a 2003 H2 with 68,000 miles that has had the check engine light on for a couple weeks. I dug up my Predator, plugged in and I had code P0135 025 Heater circuit, Bank 1, Sensor 1, malfunction. I cleared the code and drove a few miles and check engine light came back on. I know its the o2 sensor before the cats but what side of the truck is bank 1 sensor 1 on? I was going to buy one at the local parts store and they have a universal one that I have to splice the end on I quess? Its a bit cheaper than the oem. Any suggestions on best place or kind to buy?