[viciousk]

I have AR catless downpipes installed and my cars been running rich and loss of power.

I got these 6 codes:

P0420 - Catalyst system efficiency below threshold bank 1
P0430 - Catalyst system efficiency below threshold bank 2
P0304 - Cylinder 4 misfire
P0305 - Cylinder 5 misfire
P0306 - Cylinder 6 misfire
P0300 - Random multiple misfires

I'm guessing I need to replace my o2 sensors and did some research but still not sure which ones and part number. Any advice?

Thanks

Edit: brought it to the dealership and i had a faulty hpfp they replaced under the recall

[135Pats]

Pre-cat o2s would be the first place i'd consider.

Edit: for context, the post cat o2s simply measure efficiency and have nothing to do with lambda targeting, so in this case perhaps you would want to consider replacing all four.

[viciousk]

Originally Posted by 135Pats

Pre-cat o2s would be the first place i'd consider.

Edit: for context, the post cat o2s simply measure efficiency and have nothing to do with lambda targeting, so in this case perhaps you would want to consider replacing all four.

Thanks would the bosch 17098 part fit both pre-cat sensors? Like this one: http://www.amazon.com/Bosch-17098-Ox...1&s=automotive

Are they both accessible for replacement from under the hood or do I need to get under the car? Couldn't really find any DIY for them

[135Pats]

Looks like the right part but check ECS or Turner for the exact part number, be it OE or OEM. O2s get smoked on all platforms, just the way it is when they sit right off the hot side.

You can get the top side connection no problem, but the downpipe you'll need to get under the car for. O2s are not hard, but frustrating.

[Crazylegs]

i had all the same codes ended up being my dme...