Hi Folks,
I'm sure this has been talked about enough but I would like to know if there is any current additional information out there. Question being I have a 2005 supercharged XJ8 with the Bank2 rich code, and was wondering if there are any common reasons for it, one more question is Bank2 on left, or driver's side?
Thank you!

 

Hi Vettecat,

I've been chasing rich codes p0172 and p0175 for ages on mine and I haven't managed to find the reason yet.

It might be a good idea to look at fuel trims both long term and short term which will help other guys on here to help.

Bank 2 is on the left (drivers side for cars in the US). Bank 2 is for cylinder 2, 4, 6 and 8.

Thanks,

Chris

 

Best way to check for leaks is to use a fog machine, yes like a party fog machine. You can buy one for about $30 on ebay. Go to your local hardware store and buy any hose that will connect to the fog machine. Tape the hose end to your intake and voila turn on smog machine and look for fog coming out. This is the only way I was able to track down a leak at the brake booster hose which I had already replaced along with the collar but this showed me that it was still leaking. Upon further inspection I noticed the rubber o-ring inside the throttle body fitting was gone. Pressed in new o-ring, problem solved. (FYI,I did not replace the brass fitting that houses it, just the o-ring within it)

Other than that it could be valve cover gasket, which would be a good time to replace anyways since the seals for the spark plug wells are probably leaking oil at this age. Might as well change spark plugs if you haven;t done so yet. Valve cover gasket kits with grommets and seals are cheap and easy to replace. Rockauto has them. I had the opposite bank on mine leak.

 

I will check valve cover gasket!

 

I had these codes and upstream 02's cured it.