Hi everyone
I have a 2008 ford escape xlt v6, and after i had problems with it not reaching high speeds and not accelerating probably i took to a shop and they said that the manifold exhaust cats are clogged and i need to replace them.
my guess is there isn't a legal work around so i have to buy two cats and replace them. the problem is i don't know anything about the parts i need
i know that it has three cats one down in the rear near the exhaust pipe and two near the engine. and i want to replace the two near the engine,
so what parts should i be looking for because i don't know their names and if i should buy gaskets or anything else?
thank you very much

 

First thing is to find the cause of the failure, or you will be buying a second set or more until you fix the problem.
The catalytic converters are built into the exhaust manifolds on the 3.0. You can purchase after-market versions that will get the job done, legally, except, AFAIK to date, in CA, where CARB will not bless them. CARB will only accept OEM manifold/converter assemblies unless an aftermarket has gotten their product blessed.
I have not priced exactly, but figure close to $600 for the pair. Check with the site sponsors, RockAuto, and any online or local source for actual prices.
Many times failure is caused by spark plugs that fail (high mileage, and no change done) or COP (Coil On Plug) units that fail, either causing unburned fuel/air to be plopped into the converter, where it lights off, burns, and melts the converter substrate, causing blockage. One other cause is the computer failing, causing misfire, as it 'drives' the COP units to produce spark, and additionally, drives the injectors to spritz the fuel. If the computer shorts, it can cause an injector to squirt fuel continuously, and that will also cook a converter.
To change, you need some metric wrenches, socket and ratchets, and extensions. Ramps are handy to gain access. The manifolds will have to be disconnected from the cylinder heads, from the exhaust pipe, and the final converter removed, and replaced. Some will gut the final converter in the exhaust pipe, if it has been plugged by detritus from the other two converters turning into melt, but I cannot attest to the results.
Main problem that I would see is getting the manifold fasteners loose from the cylinder head without breaking the studs or bolts, or shearing off the heads. You have Fe & Al mixed, and they will corrode, making removal difficult. Squirt liberally with PB Blaster, or a 50:50 mix of ATF & Acetone.( as good or better than PB Blaster, from studies) Let them soak before trying to remove and pray that the fasteners did not get married and don't like each other too much.
tom

 

I would also not rule out replacing the main one. At a minimum, it should be inspected while the exhaust is being disassembled.
Removal should be fairly easy and straight forward. You should be able to see light through it once removed.
In fact, a very easy test is to first (before any work is started) start the engine and step hard on the gas pedal for only a second (careful not to allow the engine to reach high RPM's) and note the time it takes to reach about 4000 RPM. Then seperate the exhaust at the flex joint right in front of the main CAT and start the vehicle. If it sounds loud like it has no muffler, the front CATs are shot. If it still sounds fairly quiet and the throttle response is improved, the front CATs are probably in OK shape and the issue is the main CAT or elsewhere in the exhaust system like the main CAT or the muffler.