hi i'm billwelcome to just answerplease remember I am NOT there in front of you! my answers are based on your information. first start with the P0420 which is a catalyst failure, these do not rattle when they fail they plug and restrict the exhaust flow, the positive test to determine if the cat is plugged is simply remove teh front oxygen sensor and drive teh van if it runs ok the cat is plugged this MAY be covered under federal emissions warranty IF you have under 80,000 if you are just over but under 100,000 miles call chrysler customer assistance and see if they will help (good shot they will)
as for the egr codes you MUST disconnect the battery to clear all the memory and force the engine computer to relearn the egr valve ,it learns the egr valve and compensates for normal wear during driving and if you do not do a battery disconnect the engine computer will think the old egr is still there and set false codes
as for the oil usage first the failed catalyst can cause oil burning due to excessive engine back pressure second a pcv valve that is sticking open will draw oil into the intake and cause more oil usage, third understand this engine uses some oil the standard for oil consumption is 1 quart every 750 miles due to the low tension oil control rings used.
It has 113000 miles. Would that catalyst possibly be covered for warranty? Also Which O2 sensor do i remove. the one just before the cat or the one closer to the engine? Thanks
the one before IS the one closer to the engine it is under the windshield on the rear exhaust manifold.
as for warranty well you can call chrysler customer assistance and see what they say, depending on how you present your case who you get and your attitude (the friendlier the better) you may get some assistance how much will depend on the person you get, i have seen them give a 150,000 mile grand cherokee a new window regulator, give a customer 2 cylinder heads AFTER some independent attempted a repair and screwed it up badly on the other side they have denied claims for assistance just just over teh basic warranty expired for no real reason.
i see you provided a NEGATIVE rating can you explain as to why?since you have yet to accept the answer or done what i suggested yet, i could see the rating if you had done what i suggested and it failed to solve the problem BUT...
well with a cat code that means the cat is no longer working our diagnostic procedures the only fix is to replace the converter,if you use a cheap aftermarket one the code can comeback, i also usually change both oxygen sensors since they have a life of 100,000 miles and are usually damaged by a failed converter.
if that fails the only other thing would be a cracked and slipped flywheel the crank sensor tone ring is on the flywheel and it is common for it to break and slip retarding the timing the way we see this is with a GOOD data reading scan tool looking at the cam and crank sync if it is about 13 degrees negative this will cause retarded timing lack of power NOT always set a code and possibly cause the converter to overheat melting the insides.