Must admit I did miss that but even though still sounds like a MAF, was it new or secondhand?

There isn't much else that can go wrong without a code showing

 

I tried both a new sensor shipped from china and then a brand new complete unit from jag. I may soon have tons of used parts if I give up and just scrap the car. $12,000 in repairs in just 4 years!

 

Have you tried measuring throttle percentage with an OBDII reader? Maybe your throttle is grossly misadjusted.

 

The throttle percentage seems to track the pedal but I'm surprised that the percentage load shows 20-30% when not driving.

 

Comment removed...I had misread your post.

 

RagtopXKR, Just to be sure, you say the "load" which is "engine load" is 20-30 % at idle, not throttle position, correct? I think 20% load at idle is normal! that's what my OBD reading is.

 

Ok so 20% engine load at idle is not a sign of trouble. I have been soaking the catalytic converter bolts and O2 sensor threads in PB blaster so I hope to be able to get it loose soon. The local shops and dealer are just as perplexed.

 

On a couple of posts, you said you installed a new fuel filter and knock sensor "last week". Was that before or after the problem arose?

 

The problem started 3-4 weeks ago so all of this work was done after the power loss.

 

I disconnected the bottom of the front catalytic converters and there is much less air comming out of the passenger side. Sit down for this one...... Jag wants over $2000 for one!!! List is $2500! Holy sheep sh*t.

 

Nameless Performance makes an aftermarket set that is much cheaper and should flow better than stock.

A number of forum members have used them but they are basically made to order, so can take some time to get.

 

Got it! One of my catalytic converters had fallen apart inside. If I had unbolted the exhaust earlier I could have saved a bunch of time and money. I'm glad I did not trust the muffer shop. Lesson learned the hard way! I think this also explains the excessive oil comming out the breather into the intake. Too much back pressure. Thanks for everyone's imput! Next time we'll know to point this out.

 

Glad you got it figured out.... Good call Anders!!!

 

 

 

Bottom Line...


Symptom: Very low power output. No OBDII codes.


Possible Cause: Catalytic Converter "Downpipe" clogged from internal damage.


Test: Open up exhaust tube and observe exhaust flow coming out opening.


Instructions for a driveway mechanic.
Safely put car on ramps and remove the two 13mm nuts at the base of each downpipe.
Soak those darn rascals in penetrating oil first, and use your air impact driver for these.
(I had to cycle my compressor's power, to store the full air charge my tank, to insure I would break each nut loose.)
push exhaust pipes rearward to reveal opening.
Then start car if you feel much less flow on one side then bingo.

Even easier, I could feel the difference in how it the defective unit warmed.
When the pipes were open, the defective unit heated near the top and the whole unit became warm quickly.
The "good one" heated at the bottom first and the it's top felt cooler longer than the "bad one".


Fix: Removal of this is kind of of a pain every by my driveway knuckle buster standards.
You need unscrew the little shroud (two little 8mm bolt and two little T-30 torque screw) and it away. push
That will give you access (not much) to the 4 upper nuts retaining at the top. Even though I soaked these three of the four twisted in half.
Disconnecting the two O2 sensors at the base of the throttle yielded some blood as did those little T-30s.
A couple more easy 13mm bracket bolts on the bottom and you'll have it falling out.

I call the parts counter and the dealer wanted $2500 for one of these.
Online they are around $400.

 

I can recommend the nameless cats, very, no VERY nice workmanship BUT the are appx. 4 weeks from ordering and they are not the best comunicators, like you will get an automated confirmation of the order then don't expect to hear from them for weeks until the cats ship.
These guys are honest and do great work, and also sell 200 cell high perf. cats for appx. $900 for both.

 

Yes Anders and Dsnyder suggestions were very good and on early too! I could not find anyone willing to pull the O2 sensor. I tried myself both on the car without luck and now on the bench and the hardened (cheep Harbor frieght) O2 tool just spread out and stripped the lower sensor. Opening the pipes would be easier for anyone else in this spot in the future.

 

My Jag has been on ramps for 4 weeks front up.
Last night I pass and see the interior light is on. I look inside and the odometer is on. I press the light switch and I am ignored. I can only think to put my key in and try to turn off "Chrisitne". I find it is off ready so then I ...I turned it on. It did not like that and begain to list every failure it could think of. Including gearbox fault. I've since removed its power and I'm feeding the battery with 5 columbs per second to revive it later. meanwhile I've also adjusted the earth 15% away so the car battery will be more level, hope no one noticed. This has happened before and only the dealer could clear the transmission codes. I think a weak battery is at fault.

 

Once it becomes 'Christine' due to a very low battery, it may need a hard reset even if the battery is now charged. Definitely try that before running to the dealer.