On a 3500 mile round trip headed home. Head of the day today check engine light comes on and stays on. Car runs the same. Book says emissions system. If it starts flashing may go into limp mode. I am about 800 miles from home. Hope it is just an 02 sensor or something. Car has 19K and the replaced and 02 already. What is common what is worse case? Thanks. Car has run good. Getting 23 to 26 MPG depending on wind and grade cruising 82ish.

 

Stop at car parts store and ask them to read any codes being thrown. You should then be able to look it up to pinpoint the issue.

Here is a link to O2 sensor codes:

https://www.walkerproducts.com/o2-se...e/obdii-codes/

 

Quite likely to be an 02 sensor. If so, it is an inconvenience but Jaguar will cover it as a warranty claim for 15 years. The other possibility is an injector - these are the two most common causes.
Regarding the latter, it is a good idea to run a can of injector cleaner in a full tank of fuel, one of the best being the BG44K Platinum.

 

Thanks- Will do in the morning or maybe tonight. I afraid if they plug in to the OB2 on the road it will drain the battery overnight. Had that once.

 

If you are worried about battery drain after OBDII port access (a reasonable concern), then just disconnect the negative battery lead on the trunk floor for 30 seconds. That resets everything.

 

Could be as simple as the gas cap. Check that the seal looks good and it's on properly.

I remember there was a software update for my 2016 related to O2 sensors. I think it opened up the tolerance a little to avoid false fault indications. I still had a sensor replaced under warranty though.

Good luck!

 

Not easy while traveling with no tools.

 

Made it home. Car ran fine no change at all. Had some great highway today in CO. Nothing like a car with a blower in the mountains. I am thinking O2 sensor but I will keep everyone posted. I also noticed the temp gage is not working at all. Good items for warranty. Car was a good road car covering about 4,000 miles and a very good pace. Never got less than 23 MPG and best was 26MPG.

 

A chap on the UK forum recommends carrying a small adjustable spanner for just this purpose!

 

Going to toss a few tools in the boot. Have a can of injector cleaner in the tank now. Code was P0170 left bank fuel either lean or rich. Could be injector, MAF, o2 etc. Light has gone out but I left the code for the dealer. I will take it in next week and let them have a go at it. Have about 40 day of warranty left.