Two weeks ago i was at Epping dragway and blew a coolant overflow line when i had a bad start with a whole lot of wheel spin. Fixed line to get home but the lights started pulsating and airbag light came on. Pulsating lights i figured was from wet belts but the airbag i was unsure about. The car then went into restricted performance mode shortly after and had to disconnect battery/reset 3 times to continue home. Resets did let me drive for short periods above first gear but eventually i was stuck in restricted performance mode no matter what (that was a fun trip home). The alternator went bad or showed its age amongst the bad coolant line and wet belts. I had the same thing happen to me in a c1500ss during a burnout, except it went totally dead immediately and there was no blown hose. After replacing the 7 volt output alternator, both belts, and the hose with the proper replacement the car is good to go. Drove it 150mi and back to the British Invasion in Stowe VT yesterday with no quirks. Also heading back to Epping soon with new SC belt and freshly installed 11385 magnaflow tru x center muffler with no other mufflers/resonators. BTW best time i had was a 13.7 that night. Cheers

 

Can o2 sensors cause a restricted performance? The code says all four are bad.

 

To answer your question directly, I assume you could get a RP if 4 sensors were failed in some mode. However, there is no "code" that says 4 sensors are bad and furthermore it is unlikely that 4 would fail at the same time. If they failed one after another, you would have some seriously degrading performance along the way.
So, what codes were read, and how were they interpreted to conclude 4 sensors were dead?

 

Symptoms: RP randomly- both cruising at highway speeds/slow/waiting at stoplight. Happened every 15-20 miles.
What I did:
Switched battery
Cleaned throttle body
Seafoam in tank
No RP for 200 miles now.
One thing though- when I removed the throttle cable to take off the TB, the return kind of snapped back as if it was stuck a little open (not the butterfly, just the part that the cable moves) I may have had that too tight.

 

I have a 2002 xj8 sport with a restricted performance light, at idle it runs ok when it is put into gear it starts shaking. Any info would be greatly appreciated

 

The first step is to stop by Autozone or other auto store and ask them to read the codes, then come back with the actual codes, not their interpretation.

Also, please visit the new mwmber area and introduce yourself:

New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

 

Next step is to start with a new thread.

 

I'm sorry it's taken so long the RP problems I was seemingly perpetually faced with were solved last week and boy did I feel stupid.
I feel I must bring up to date anybody who is not aware of my problem.
My car is a 2000 XJ with a V8 engine and for some time the RP message came on at what seemed to be the most inconvenient times, as it did exactly that, restrict performance.
Recently I had some awful experiences culminating in my taking it to my mechanic's in order to have it properly diagnosed (not cheap!). It turned out only to be a misfiring plug. Being as the cheapest price I could buy them is £9 plus VAT I only replaced one! My only excuse is that I thought the misfire started when the RP message came up! Since the everything is aok now I must apologise for suggesting to people that it might be a little complicated.
I am retired now but when I taught motor mechanics to offenders a few years ago one of my lessons was to make my students stick to the KISS principal (Keep It Simple Stupid). I find it a bit embarrassing that I failed to operate that principal myself!
May I take this opportunity to thank all those people who tried to help me. Although I hope it doesn't baffle me again I can assure you that I will contact this site immediately should it.
Richard Major.

 

Don't beat yourself too much, Richard. I doubt anyone on here who was being truthful could say they had not done the same thing at one point or another! Look up "Occum's Razer"