I had a 2004 s type with a v6 and it has a p1646 o2 sensor code and it won't upshit right. Read about it on my blog

Jaguar HELP!: 2004 Jaguar S-type won't upshift

 

daxter congrats on the fix.

I also know that if the vehicle has a vacuum leak that the transmission will shift incorrectly as well. Throwing no transmission codes or engine codes.

BTW, I visited your site, nice. In the above link you posted, there are a couple of typos in the last paragraph that starts with "With the Jag IDS"

 

I've lost count of the number of times people say they have a transmission problem and members here point out that it's likely caused by an engine problem (and nearly always turns out to be so). And that's when there are NO codes or only trans codes. Any time there's an engine code just fix it before thinking it's the trans.

I've said why this is so enough times

Good to see it yet again.

Now... how to get future members to read about it LOL

 

I agree but I still have to check as much as I can since Im a mechanic and the customer likes to here right the first time. If it was my car...