eyeball06

I have been chasing a CEL for about a year. It started as a bank #2, sensor #1 A/F ratio issue. I replaced it, CEL continued. I started to get misfire codes(300,302,304,306) and bank #1 A/f ratio sensor codes (171 and 172) also. With the engine not trimming properly, I ended up clogging the back cat. convertor. Over the course of the past 12 months, I have replaced the Bank #2 A/f ratio sensor, the back cat, spark plugs and the Mass Air Flow sensor. I have used about 3 cans of carb cleaner chasing vacuum leaks. The car is still running rough and at idle all 3 front cylinders(bank#2) are not firing. I can take the leads off all 3 of the front coil packs and it does not affected the idle. They will fire at high RPMs (3000) but the car is essentially undrivable. I have also developed an exhaust leak ahead of the bank #1 cat. Faults I get now are the 172/171(bank#1 A/F ratio issues), 1150 (Bank#2 A/F ratio issue) and 300,302,304,306. Before, I buy VVT actuator, temperature sensor and so on, does anyone have any ideas. If I replace the cat will the 171/172 go away, even though they are in front of the cat?
Thanks in advance,

salimshah

In retrospect, maybe a better choice would have been taking the vehicle to a professional mechanic.

Did the misfire happen after timing belt change (you can be couple of teeth off). OCV also pushes the timing and since they are all on the same bank, the chances of OCV going bad are high.

Cat issues happen when you ignore the CEL for a long time. Old adage applies .. stitch in time saves nine. [<- not directed at the OP, but for benefit of readers]

Salim

eyeball06

Where's the fun in letting someone else fix it. And I think the appropriate proverb is "An ounce of prevention is worth a pound of cure"