Yes you can inspect them the way you suggest.

However to clean them the safest way, without getting stuff in the engine, is to take them off and soak them in something that will remove soft carbon.

For that the SC has to come off unfortunately.

 

I felt the same, 25 more. First was plugs at 105,000 and then all four O2 sensors at 115,000 Used OEM. Think this was maybe 25 RWHP. Was rich on bank 2 and “slow” on bank 1. Both fine now. Plugs and sensors was under 400.00 USD.
Would love to clean the inter coolers. But looks daunting.

 

Hey quick question I never seem to get a good answer on. Is there tuning available for the post denso ECU xjr's? If so who and anyone in the states can do live tuning? Thanks

 

I searched for this a while ago and back then one UK company told me that they would "try" but only guarantee a 50% chance of success.

I think that Cambo did it back then however no longer does this.

But things can change like the Quaife LSD which Quaife stopped selling back then and sold all its inventory apparently is selling it again!

 

I sent mine to UK to get tuned. Its expensive compared to how much HP/$ you get on tunes for other cars.

 

Reprogramming the ECM can really provide gains with a turbocharged engine. Adjust only the waste gate to increases HP. Like going 30 over on the pulley.
Adjusting timing, valves, F/A ratios, and knock sensor parameters is time consuming. Since the XJR runs rich by design, there is hp available here.
Most turbos are detuned enough that adjusting the waste gate pressure might yield 40 - 50hp. I doubt a ECM tune can do his.
Downside, like running a 20 or 30 over pulley, jacking up boost can create issues over time.

 

Well My Porsche TT had hugs gains....My reasoning for the question always is not so much about power, but how the car handles it. Torque management, throttle response and other things. Also I have the 2.6 Big bore Kenne bell twin screw and wa sthinking of upgrading my xjr to a newer one if it could possibly be tuned better. Id also think of going E85 if I could. So its more than expecting huge power gain . That's not really what I want a tune for.

 

If it's a Denso ecu past 07 I can mostly likely tune it. There is tons to gain on a 4.2 later model car. I'm at nearly 100hp gain on my 08 XKR and majority of the gains are in the tune.

 

I would love even 25 more. Is there that much more to gain from a x358?

 

I can try it , are you in the US?

 

Im wondering if anyone knows where to get any modification for a 2016 xj r-sport ( Supercharged V6). I am trying to find specifically an exhaust but i dont know if they are premade or I have to go somewhere to have one custom made