Emissions Problems

[itsdacheese]

<_< Howdy ALL, can anyone tell me what is the most common emission parts to go out on a 2.9L motor .I am getting a emmission lite and it wont pass California smog at this time and I put 2 new CATs on it and new exhaust system. I have put in a new O2 sensor. ANY info on this surely would be appreciated AND its nice to be here with other BroncoII owners
Cheese B)

 

[BigNasty]

I usually find the EGR valve to be the one part that goes fast..


In any event, you really need to pull the codes on it to find a starting point rather than just throwing parts on it and hoping it will work...
BUT.. after changing the parts you did change, did you disconnet the battery for around 10 to 15 minutes in order to clear the codes?
It is possible that you fixed the problem and don't know it yet if you didn't clear the codes in that manner.

 

[Wliebhard]

Also, in addtn to what 'cheese said, I found that a basic tune up- cap, rotor, plugs, wires ect..... worked well on my 5.0 stang and 351 bronc. Let the motor warm up to operating temps too, and you should be good to go, or at least on the right track... Does Cali have lo and high speed emissions?( I'm From New Mexico )
If so, try to see what you are failing- NO, CO, ect., at which test; that should also help you narrow down what's going on. Smog pump, ect.... Finally, get yourself a repair manual and make sure your rig is in good running order as far as the oil change goes, fuel filter, air filter, plug gap, you get the drift.

 

[monty06]

i'm in florida we have no more emissions down here so i down have any exhuast item on my truck

but egr valve is sometimes clogged i would clean your intake upper that is
manifold sometime crack stock manifolds suck
o2 sensors cat's i assume you have both the two stage cat system and a good muffler with no holes etc..
i would do a tune up on it before the test dirve it around for a while so when it comes time to doing it the engine is nice and warm