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TIM MOHR, ASE Certified Technician
Category: Jaguar
Satisfied Customers: 15842
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2003 jaguar 2.5 xtype p0301 p0303 p0305 p0420

Customer Question

2003 jaguar 2.5 xtype p0301 p0303 p0305 p0420
Submitted: 11 months ago.
Category: Jaguar
Customer: replied 11 months ago.
Expert:  TIM MOHR replied 11 months ago.

Hi, my name is ***** ***** these codes, you most likely have bad gaskets on the #1 bank intake manifold, it is showing a missfire on all three cylinders on that side, have you checked for a vacuum leak on the #1 intake manifold bank?

Customer: replied 11 months ago.
I did I didn't find anything leaking
Expert:  TIM MOHR replied 11 months ago.

hw did yu check it? did you use a smoke machine?

Customer: replied 11 months ago.
Before the code it used to have one code only I guess by not fixing that code the other ones come up it was p0420 which it still there
Expert:  TIM MOHR replied 11 months ago.

when there is a missfire i one or more cylinders, it can cause the cat converter to plug up, thus the P0420, but before the cat is replaced, you need to find the cause of the missfires, if all 3 of the cylinders are missfiring on bank one, that rules out an ignition system fault, so Its either going to be a leak in the itake manifold gaskets, which is very common on this engine, or possibly a bad hose going to the PCV valve, which is also common, have you checked the elbow next to the PCV valve, its cracks very easily?