I had a thread involving a constant p0430 code. replaced sensor, no luck. in my hopes that it wasn't my Cats needing to be replaced- I finally checked another issue "exhaust leak" as listed here.

I found a 2.5 inch long crack in the drivers side exhaust manifold.

I know this is fairly common on these JKU's, but I am asking is if the people that had cracked manifolds also had the P0430 code because of it.

I obviously am changing the manifold either way because its damaged, but I would like to know how good of a chance I have at solving my code issue with a new manifold.

any help is greatly appreciated ( I need to get this puppy inspected soon! )

 

A cracked exhaust manifold will cause the code. Its not letting the o2 sensor read properly.

 

thats my theory ( and hope ). I just ordered the part online- so hopefully the beginning of next week I will find out just how hard it is to replace.

 

I know alot of people experienced cracked exhaust manifolds, can anyone else chime in here

 

well the exhaust manifold has been changed, i hope this fixes my problem!

 

Please post if it stops throwing that code. What year is your rig?

 

2007 sahara unlimited with a 3 inch long crack ( you could easily see daylight through it when removed ).

I will definitely let people know. my opinion is that too much air entering the exhaust system will cause the sensors to be off, and subsequently causing it to throw that code. but only time will tell.

 

Were these cracks audible to you fellas? I'm a little concerned about my JK, but it doesnt look like it's a fun job to remove the heat shields to check. Approaching 115K miles, and the exhaust hardware is looking rather permanent.

Edit: Also, I'd feel pretty confident that replacing the manifold will fix the P0430 code.

 

thanks, I need all the 'yes it will fix it' replies i can get- it just makes me hopeful not to have to spend a paycheck to get new cats.

as far as the heat shield removal. its a cake walk for anyone with 5 minutes of time and a 10mm socket with a few different length extensions ( depending on how much clearance your actual drive is ). I was actually surprised how easy it is.

just take the 2 top bolts off, reach down and get the 3rd- take the bottom half of the heatshield off then wiggle around the top half until it pops out. if it is cracked- you will notice. the crack on mine was huge.

 

UPDATE:


manifold swapped out, check engine light is BACK ON... looks like im gonna be spending a chunk of change on a worthless cat swap even though the truck runs fine.... thanks jeep