Just recently, my truck has been throwing codes. It started off with a P0101. I cleaned the air filter and the MAF wires and that was fixed. Then the truck started throwing P0172 and P0175, running rich on left and right bank. It would come and go for about 2 months. Now tonight, it threw a P1133, o2 sensor insufficient switching left bank.

Around the time all this code throwing started, I put a bottle of octane booster that my friend gave me. Could this be a cause?

 

sounds like that is the prob. i am guessing you have a-tap? if so you can go into the section that has all the numbers that change while loging. sorry dont know what to call it. look at the front o2's and the number should be shanging rapidly at idle. should be like 500-800 range. this is how i was told to check them. sorry i can not explain it too well maybe some one else can help.

 

How many miles are on your ride? Is this bank one or two for the O2's? I ask as your cats could be potentially bad if it is bank two.