I just changed coils 2,4,6 and spark plugs.. last code read before today was 02 sensor upstream bank one needed to be replaced.. stopped at a local AutoZone and decided hey what the heck let me read the codes again.. now there id's no 02 sensor code p146?. Now there's misfire on cylinder 1,2,3,4,5, &6... Is this even possible? Even tho I just changed the whole passenger side

 

Sure, various ways, such as you may have left an air leak.

Read fuel trims or try a smoke test.

 

Are these good quality?
2001-2006 Jaguar S Type Intake Manifold Gasket Set - Engine Mechanical - Felpro 01-06 S Type Intake Manifold Gasket Set - 546-07023701 - PartsGeek

 

If your car still has the two factory Intake Manifold Tuner Valve O-rings (yellow in color), replace them with the improved version (green in color). The factory IMT O-rings are infamous for leaking and causing misfires. Get Jaguar part no. C2S40669. You'll need two. Should be less than $8 total at the dealership. All 3.0 V6 S-Types suffer this issue sooner or later. Very good tutorials here on the forum to walk you through the process. Search for "IMT Valve O-rings short route" and just do it....

 

I did not see it but be sure and have all codes cleared everytime you get them read.

You always want to fight the new codes that repeat and come back. You can get odd random codes too. Just so much better to start off fresh when troubleshooting.
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Yes I have just replaced then with the new green ones about 2 weeks ago. So I'm assuming it's the manifold gaskets since I partially removed the manifold to change the coils and plugs

 

That's y I need my own personal obd tool.. auto zone/advance auto parts won't clear them

 

elm327 starts from about $5.

 

The way I see it. I don't know what you mean by "partially removed manifold (plenum)". By partially removing you had ran the risk of cracking one of the vacuum lines that are known to become extremely brittle.


If you are going to replace the "manifold (plenum)" seals you might as well replace the lower intake seals (gaskets) as well. It is not much more involved and believe me you most likely need to. You might want to have on hand some 2 part epoxy, there are 4 bolts that hold the lower intake onto the motor, there is a chance that one or more of the brass threaded barrels will likely spin and not release the bolt(s). Quite simply once the lower intake is removed use a pair of pliers to remove threaded brass barrel and epoxy back into corresponding hole. FelPro has these seals (gaskets) available.


Did you have a look at the spark plug wells, using a flash light you need to look down into the wells odds are you will see some sort of oil that has seeped into the wells. With the plenum and lower intake manifold removed, NOW is a great time to change at least the passenger side seal out.

 

When I say partially it's because I removed all bolts, connectors, hoses, and still could not get the manifold completely out of the engine bay.. so I shifted it to the side to get to the coils/spark plugs.. initially I only replaced the spark plugs on the passenger side(and there was oil in the wells then) but when the codes didn't leave and the car was still shaking violently upon cold starts. I then changed all the coils on the passenger side.(No more oil in the wells &again only partially removing the manifold ) since the shaking disappeared but is now returning but definitely not as bad.. After that I had the codes removed.. immediately after I turned the vehicle off then on again.. check engine light came on stating I had as faulty 02 sensor upstream bank one. Only thing I've done since then is replace the imt valve o rings with the green ones.. recently had codes read again to see if any thing else had appeared n surprisingly the p1464 code is gone and now there is misfire on cylinder 1 2 3 4 5 6..so as u said I figured I damaged the seal on the manifold.. so next I pan to change the seals and follow your suggestion as well and change the lower portion.