I recently bought a used 2000 jaguar XJ8 and have been working on it for about three months. Secondary tensioners are aluminum, haven’t checked primary. I also replaced the O2 sensor and changed the spark plugs and three misfiring ignition coils. It didn’t have restricted performance when I took it out this morning but after bringing it back and letting it sit the engine starting shaking really bad and it put it back into restricted performance. When I took it out it was running really well for a bit then started to not respond to me pressing the gas pedal, or lagging for a few seconds before shooting up then back down in RPM (I attached an OBD2 scan below).

What do I do now?

 

Replace both knock sensors. And try running engine again without any codes.

 

Make sure that the cylinder #2 ignition coil electrical connector is fully connected. You could also use a small flathead screwdriver to push in on the actual round seal going into the coil gently but firmly for a more positive connection. It’s not uncommon to find a single wire not sat as like with everything plastic under heat, it’s brittle and vibration works things loose. If cylinder #2 was one of the coils you replaced, I’d say look for a better brand of coils instead of the cheapest ones you can find.

I agree with Vauxi on replacing the knock sensors. They can be replaced with the intake manifold on the car but it requires **patience** and a few special tools.

 

If I’ve already replaced the knock sensor on the passenger side (US) should I do the second one to?

 

Was that P0327 B1 KS code there before you replaced that sensor on the P/S?? I have ran across before that the 2 electrical connectors were criss crossed where someone was trying to diagnose if the code moved by swapping the connectors side to side. If you aren’t sure, you can post a picture of the connectors on here. Did you install a new or used KS?

One last thing, if you know you have a misfire on #2, fix that first before you deal with a KS.

 

I borrowed a buddies obd2 reader and this was the only scan I did, I tested the spark on the ignition coils and I replaced the coils that didn’t, then it was still in restricted performance so I changed the sensor and the restricted performance went away, then I drove it and it ran quite smooth for the first few minutes then wouldn’t react to when I applied the throttle almost feeling like something wasn’t catching with the transmission. I took it back to the shop and left it idling for a bit. Then the engine started to shake real bad and it put it back into restricted performance.

 

If you plan on keeping this car, I highly suggest that you get a good scanner. One that can read live data in the ECM while the engine is running. Reoccurring codes are what you’re after. Weening out what’s real and what’s not (new codes that pop up after you cleared them) is also a clue. Search this forum for a good cheap scanner recommendation. When looking at one, make absolutely sure that it lists your car as far as connectivity.