.......well i am one of the lucky ones....got through the hurricane and noreaster.....relatively intact....compared to a few friends of mine at the jersey shore.....

but durring the gas shortage...and against my best judgement.....i put about half a tank of regular gas (which means lower octane) in my xj8-l.... all that was availble.....the car ran fine for a few days and than i started it up yesterday and the engine light stayed lit....after the car started up...

the car runs fine...idles well and is as quiet as usual....so performance wise no noticable difference....so i am wondering will this go away when i put high test in the car...and perhaps some dry gas in the tank.....or do you think i have damaged the oxogen sensor.....thoughts/suggestions welcomed....

 

Please add your car details to your signature to make things easier - you have a 2000 XJ8 I believe?
I run my XKR on the cheapest petrol I can buy with no problems.
Can you get the OBD codes read - either buy a cheapo reader or take it somewhere where they read the codes for free.
You do need to sort this even if the car seems fine.

 

thanks steve.....i may be able to get a code read to see whats going on...yes its a 2000 xj8-l.....the owners manual says to use premium fuel....i do not know what your 2004 requires but i usually put in 91 octane....

either way you are right....need to figure out whats going on....may have nothing to do with the gas i put in the car.....thanks for your feedback

 

Any codes from your OBD reader?
If you don't have one, check out this part of the foru

https://www.jaguarforums.com/forum/g...oved-**-33347/

 

Very low risk that you have damaged anything with short term use of lower grade fuel.

The illumination of the CEL is more likely related to the fuel quality (water or other contaminants) rather than its octane.

As has been suggested already, have the codes read and post them here for advice. Post the actual codes and not the description anywhere like Autozone gives for them. Generic or OnLine code descriptions often vary from the actual Jaguar descriptions and can be misleading.

The CEL will not go out by itself and will have to be switched off with a scantool. The light is there as a warning that something has been detected 'out of range' and not an indication your car is going to self destruct at the next traffic light.

Graham

 

The later X308's used 2 oxygen sensors for each bank of the V8-an upstream wideband air/fuel ratio sensor & a downstream narrow band oxygen sensor to check catalyst efficiency.

The upstream sensors are known to fail, as the design of the sensor means it has to run very hot with a powerful heating element. The heating element can fail so the sensor does not give any output.

When this happens the EML dash light illuminates & the ECU reverts to a basic engine map. This allows you to still drive the car but it's not working at the optimum efficiency level.

Get a basic cheap OBDII fault code reader & scan the system. When the upstream sensors fail they produce fault codes P1646 & P1647, depending on which bank of the V8 the sensor has failed on.

New sensors from Jaguar are hideously expensive so go to the aftermarket suppliers. If all else fails, the upstream grey plug sensors from the X-Type Jag can be bought cheaply off ebay & these work ok on the V8's.

Ask me how I know

 

thanks...grahm and red october and all that have given input......from what i have gathered thus far from this forum and elsewhere......i agree no serious problem even if i put high test back in and perhaps some dry gas..and i agree that the light will not go out even if ...if i do this.....durring the hurricane and shortages.....the quality of the gas here has been hit and miss.....however, things getting back to normal...

plan to see if auto zone will scan for me otherwise i will be getting one of the scan tools suggested from the research.....my dilemma is this.... while the car is performing well with no noticeable impairment.....that light has to be turned off before i go to state inspection.....with the light on.....they will not inspect for pollution which is about the only thing they do inspection for now in the state of new jersey...thanks again.....jagjunky....:icon_twocent s:

 

When the light is turned off you will have a code P1000, and they will not pass you until you go through several start/ drive cycles and it changes to P1111, indicating the emission system monitors are functioning correctly.

 

The EML light on my 2001 XJR came on last summer, the very next day after I'd just taken it for the UK MOT test-talk about a close shave...

I got a cheap & cheerful code reader for around £20 GBP. It came up with fault code P1647, which was the heater in the one of the upstream oxygen sensors. The car still drove alright, although the fuel consumption was a little higher & the power a little lower

When you find the fault, fix it & reset the EML lamp, the system has to go through several 'drive cycles' as RJ237 says. This is to allow the ECU to test the engine management systems under a variety of different driving styles-steady cruise, hard acceleration, full throttle, high engine revs etc.

Initially, it shows up as code P1000 before all the driving cycle tests-if these are then completed satisfatorily the code changes to P1111 & everything is ok.

So your repair procedure should be:

1) Get a cheap OBDII code reader & scan the system for the stored fault codes

2) Cross-refer the fault codes to the Jaguar P code tables which can be found online

3) Locate the failed component(s) & carry out the repairs.

4) Use the OBDII code reader to reset the EML light.

5) Go for an extended drive, making sure you include a cold start, full uninterrupted engine warm-up from cold to hot, steady cruising on the highway, hard driving with full throttle & the engine wound out to the maximum speed in kickdown.

6) Recheck the codes & look for code P1111, which indicates everything is alright & you can them go for the official state inspection tests. If you still get code P1000, then you need to go for some more driving cycles

 

Hopefully, i will have a happy conclusion to my problem...heres what happened over the week end....(i wil try to be brief and concise)

took the car to auto zone...and had codes read by a very helpful guy named marco the reader came up with the p1000 but linked to lexus oem to a p0455....he assured me it was the correct code for my jag....so troubleshooting yielded the following possibilities:
failed vent solenoid,loose/missing fuel cap,purge solinoid malfunction and evap hose faulty/loose
so the system was detecting a gross leak of some type

so than i figured what would advance auto parts come up with? (auto zones major competitor in my area)....

had it read again by a guy named hector....used the same reader as guy from auto zone.....got the same results re the p1000
he immediately went to the gas cap after sitting in the car listening....the car was so quiet and smoth he said....any leaks are coming from outside the engine....his guess not mine....
anyway he checked the gas cap and noticed it did not click when turned ...he examined the cap and played with the spring and reset the gas cap...still no click but tighter than previous....

back to reader to re-set eml light.....turned the car off and started up again and the light was out.....told me to take the car for a ride on the highway...and open it up a bit and to come back monday or tuesday....to check again..... (i assume this would have the same effect as the suggestion made by red october and rj237) as re re-cycling.

long and the short of it ...is the light is out ....but i will probably need another gas cap....i would be ok with an aftermarket gas cap....but am finding for the car(xj8-L)....hard to find...so if anyone knows of a source....would appreciate your letting me know....

in closeing my problem is i kind of drive like an old man although i am not all that old...rarely do over 50 mph....but when i took it on the highway and opened it up got to 80mph very quickly and car felt like only doing 40 mph....car rsponded admirably...i must say...my xj6/12...pretty gutsy but this thing flies...

as ships are made to sail this car is made to move and i have to somehow overcome the feeling that i am hurting the car by opening her up now and than!

once again and one and all thanks for the help.....

 

Glad you got a good result & nothing too serious. It's always a good idea to make the engine work hard every now & again-they don't benefit from constant pootling around & it can cause carbon build-up.

More problems are caused on all the modern emissions gear on cars by driving too slow, than by driving too fast! Catalysts & Oxygen sensors soot up, and on Diesels the DPF filters can become clogged with carbon.

The harder you work an engine, the better & freer-breathing it becomes

 

great advice ro