I had a check engine light come on last week and could use some help and advice.

P0332 - knock sensor 2 circuit low input bank 2
p0133 O2 circuit slow response Bank 1, sensor 1
p1415 secondary air system fault bank 2drive cycle d: signal implausible
p0420 catalyst system efficiency below threshold bank 1

I'm wondering if these issues could be caused by recent switch to unleaded vs the supreme. Any help and thoughts are greatly appreciated.

 

They very well could be. Stop running cheap gas!

 

like mentioned above when you switched to low quality gas. Your codes are all over but ill be more concerned with the 420. Need to address that 420 asap.

 

Thank you...will do.

 

Lro3nj.... do you think this is the catalytic converter going out? From what I've been reading on the forum, people are just replacing with "bolt on" systems? What would you recommend and thank you for your help?

 

P0420 = one or two dead cats. They are 14+ year old vehicles at this point...

Having said that, I rolled with a 420 code for the better part of a year. Both of my cats were dead but replacing them is on the spendy side. I debated having new ones welded in but finally went ahead and replaced the entire exhaust system with a Magnaflow one. Took me about 1/2 a day of work but the 420 disappeared immediately.

If you do that I'd suggest putting in some new pre-cat O2 sensors. Would probably go a long way towards clearing up your codes.

 

420 is expensive fix always as what Chrisw mentioned replacing cats will take the 420 out. But you have to address the 1415 first coz its part of your secondary air injection system. Check all valves and leaks or even connections. The vacuum solenoid and the purge valve. They should be open upon starting to warm up the cats. Or even the SAI control valve, since its only on the driver side. Your O2 sensor might be getting wrong reading on the driver side same as the cat problem you are having. You can check the knock sensor later. I think the knock sensor code are just pending codes.

 

I'd run a can of Seafoam in half a tank of top tier supreme fuel ASAP.