Ok, I have codes PO171 - Bank 1 and PO174 - Bank 2, I found out those are for the O2 sensors. I have someone to replace them but would like to know what would be the less expensive and best O2 sensors to get? Please advise!!

Also have ABS light on, have had brake pads replaced for front and back, brake fluid is full but light is still on. I was told that the master cylinder would have to be replaced. Does that sound feasible? Just asking!

I've had this car since 2003 and have had no problems at all. Car was sitting from August until present and when I started driving it, a lot of lights started coming on and I've never had a engine tune up or transmission tuneup. I was also told that since sometimes car does not go into gear smoothly, I need a transmission tuneup. So I've been looking into the parts needed for an transmission tuneup and I have seen the youtube video by Reverend Sam, that's how I got to this forum, but I have a question, is the transmission pan/filter/gasket the same in the 1999 jag XK8's as in the 2003 jag XK8 as the one that the video is based on?

So I'm here to ask questions and plead for advice pls!!!!!

Stability control failure light is on as well, this light would come on sometimes and go off after I drove for about 5 mins but now it's staying on. I was told I need wheel bearings for the front passenger wheel, hopefully that fix the problem.

Any and all help is welcome, thank you

 

Thyre not for 02 sensors but vacuum leak and sometimes on your car a mass air flow sensor. Change shops or mechanics.
Look at the air intake tube that goes from the air filter to throttle body along the ridged bellows. Theyre notorious for cracking open there with age and thatll do it. sorry dont have time to address your other issues. but 02 for those codes are a definitive misdiagnosis

 

With all those things popping up at once, after sitting, I wonder how the battery is. From reading this forum, I gather that could cause strange things like that.

My 2000 XKR only had about 5,000 miles of exercise in the last two years by the PO I have been getting codes for each bank running rich. I thought they were the numbers you stated. I'm thinking more run time might help. A few hundred miles into the attempt I'm getting the codes less often and they are resolving faster. I'm glad because restricted performance mode just isn't very fun.

 

+1. You have likely been misdiagnosed and have a vacuum leak and/or MAF problem.

You need to get your battery checked. An even slightly weak battery will cause all kinds of false fault indications.

The process to the change the fluid in your transmission is similar, but you have the earlier 5-speed with different parts.

 

I had basically the same codes. In my case it was definitely the MAF. Like others have said, low batteries cause a variety of issues. However, I always related the occasional window-drop to be associated with a low battery. In other words, in my experience with the XK, if you have a low battery you will have occasional window drop as a minimum (and of course could have much more associated with a low battery).
If you think you're due for a new battery anyhow, I'd switch it. If you think it's good for some time, I'd have it load tested, and then try the MAF. I'd clean the MAF first with MAF cleaner (that only temporarily worked for me - I had to replace it). Let us know what it turns out to be once permanently fixed.