Sadly I'm back with more issues with my Zircon! Finally got him up and running after a summer of being down and now we have issues that have him sitting again. So let's begin.

When I start him in the morning he seem to shake (my RPM would go up to 1 and half) and I assumed it was due to the weather. Once he warmed up he drove fine. This would happen off and on for a month or so then suddenly my check engine light came on and my "cruise control unavailable" message showed up and my car went into limp mode. I ran the codes and also had the codes ran at Firestone and these are the codes I got....P0300; P0301; P0302; P0303; P0304; P0305; P1313;P1316. I researched the codes and they meant misfires. So I had my mechanic change out all the coils and sparks plugs. My Zircon seemed healed with much more power. I had the codes cleared and a couple days later the check engine light came back on Scan him again and the codes I got this time was P0420. When I found out what that meant I almost passed out (Catalytic are not cheap!) but I don't believe that is my issue as the car was driving very well and I did not have poor gas mileage considering my car does short runs usually from home to work, which is about a 15 minute drive. My mechanic suggested I put fuel injector cleaner in my gas and "blow" my car out, as my fuel injectors may have been dirty due to my previous issues. I blew Zircon out and he drove just fine. Then about a week later the sputtering started again whenever I started my car (when it had been sitting, Rpms at 1 and half), so I ran the gas out and put in top grade...I had drop to mid grade about 2 years ago and my mechanic stated I needed to use the top grade as that may be causing the issue. It took forever to run out the gas, as my Zircon decided to give amazing gas mileage. So top grade in "blew" Zircon out again he was running fine. Then a couple days later (had just fill with top grade again- only half a tank) was driving around and all of sudden the sputtering started my engine light came on again and started blinking and the car went into serious limp mode and I started to smell something. So I got Zircon home and read the codes again- P0300; P0301; P0302; P0303; P0305; P0306; P0171; P0174; P1313; P1316; P0420. When it's sputtering (shaking) it feels like something is not getting through like some type of blockage. I love my Cat and it's paid for so though I'm not swimming in money more like drowning in debt, I will save to get my Cat back on the road. When he's well he's all that and more, it's when he's sick I want to slap him.
Note my Zircon is at 100,800 miles.

 

Time to run a compression/leak down test as the ECM is picking out every single cylinder as misfiring, also run a vacuum test at idle to see if the engine is making good vacuum and not struggling to exhale out of a destroyed catalyst. This is on the assumption there are no massive vacuum leaks. You said plugs and coils are new so I would rule out ignition, unless there were questionable aftermarket plugs and coils used. The old addage was there were cars that could nickle and dime you to death, Jags can hundred and thousand you into bankruptcy! Just be glad you don't own a Land Rover!

 

RealmCenter,
Thanks for the suggestions but it appears it just may be my catalyst...now I'm getting the fuel smell, sputtering continues and I noticed some rust like pieces in the tailpipe of the catalyst that has "gone" bad. I'm going to call around to have a straight pipe put in to bypass the catalyst since I will not be selling my Zircon....hopefully that will fix the issues at hand. Will let you know how it turns out. Thanks again.

 

LRL- You probably have a vac. leak (leaning out causing the O2 sensor to dump more gas) thats the smell & P0300 ,rough cold idle, if it gets to bad your converter can glow red and start a fire if parked over anything flammable. It has happened.

 

RealmCenter,
How do I run a Compression/Leak Down Test? Thanks.

 

Remove all plugs insert a compression tester one cyl. at a time. crank engine until max compression is achieved,( about 10 secs).,compression should be between 140 psi and 160 psi. your gauge probably has a check valve in it to hold the highest reading, this is not a leak down test this is a compression test.In order to do a leak test you have to know when each cyl. is at TDC on the compression stroke( all valves closed,piston at TDC),it is hard to know unless you know where to start. The best to do is if you get a weak reading is to squirt a heavy oil in the cyl,spin it over and test it again,then if you still get a weak reading you could have worn rings,leaking valves,head gasket.a little oil won't hurt your CATS,(don't dump in a cup full). A cold engine won't seal as well as a hot one but the oil won't disappear as fast either for the test.Any reading under 120PSI is a sign of problems to come.You can't eliminate the check valve in the gauge either, the pulsing will bend the needle and wreck the guage.If you want a leak test for sure then a garage might be in order
Someone on the forum might have a better idea so keep checking

 

>if you still get a weak reading you could have worn rings,leaking valves,head gasket

Actually..., in the general case if the compression rises after introducing the oil into the cylinder the usual conclusion is a ring problem. The layer of oil will serve to temporarily seal the ring but won't have the same effect on the valves.

Old time shade-tree diagnosis trick.
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Jaguar: Grace, Pace, and Space - Sir William Lyons

 

Does anyone know how the Catalyst converters are held in place...welded or bolted? I trying to purchase an after market converter and trying to figure out which one I need to purchase. Thanks.