Cat's for IM

[badcamelot]

Are cats necessary for states requiring IM inspections? My car just wont pass, hydrocarbons to high and I ve tried all suggestions except replacing cats. But Im wondering if they are necessary?
Any one know?

 

[93rev2sev]

If there's an inspection, then yes. You need cats. Guaranteed. And we don't even have state emmissions in Mi.

 

[hawkeye18]

Aren't hydrocarbons the result of a too-lean fuel mixture?

Did you check for vacuum leaks and/or a clogged fuel filter and/or a misfiring injector? The first two would be more likely. New cats may fix the problem (ok, they'll probably fix it up), but a well-running SHO engine, even at 300,000 miles, should have no problem passing emissions with no cats. Something is wrong with yours.

I suppose you tried the ol' SPOUT trick already?

 

[badcamelot]

I have not tried the spout trick yet. Nor have I had any vacuum lines checked. The fuel filter was new about 8 months ago, assuming that is ok. I was told hydrocarbons are a result of unburnt fuel, so if that was right wouldnt that be too rich and not lean? I have a newer y-pipe with cats and was in the process of swaping those out until the nut on the last ****** bolt stripped on the inside!!!!! Its on the rear manifold too, so no way for me to get at it with a hack saw or anything. SO im a little lost at the moment as to what to do.

 

[tardboy21]

pull the spout and you will likely pass. Even if your Hydrocarbs are triple the limit.

 

[93rev2sev]

The manifold is a lot easier to remove than you might think.

 

[badcamelot]

Thanks for the tips. Taking manifold off will not help (way too much work anyway) cause still will not be able to slid out exhaust.
The nut on the ****** bolt just spins either way. The hex on the outside isnt stripped, so a socket grabs it just fine, it is the inside of the nut that must be stripped. The ****** bolt itself will not turn (tried and suceeded in hammering a small socket onto the retangle nub at the bottom of the ****** bolt itself, thinking Id simply remove the whole bolt and deal with getting it off the exhaust on a work bench etc etc. But the nub on the ****** broke off! The bolt is welded to the manifold. So the nut baffles me. If it is stripped out too much to be forced up or down to bit into threads below and above, then it should just fall off right? Wrong. Im trying to tighten it back and just put the other nuts back on and run with those cats and pull the spout, but that would be easy. The nut simply spins for tightening or losening - the strangest thing ive ever seen.

 

[shoon]

Aren't hydrocarbons the result of a too-lean fuel mixture?

Almost;
hydrocarbons = running rich
NOx = running lean

cats usually burn out when you run rich for a long time... the unburned fuel causes the cats to get extremely hot and they cease to function when the catalysts burn out. If you run too rich or burn oil you get carbon which will plug the cats.

normally when all is well the catalytic converters heat up and burn off extra unburned fuel reducing hydrocarbons.

Couple things to try / consider:

-old o2 sensors (replace with motorcraft; supposed to be replaced every 60-80k miles)

-sticking piston rings (attempt seafoam or similar treatment)

-spark plugs &/or wires (worn or improper gap)

-dirty MAF (inaccurate metering of air)

-thermostat (does your temp gauge function? if not thermostat might be sticking open)

-vacuum leaks (causes un-metered air to enter screwing up ECM calculated air fuel ratios)



Use the SPOUT if your hydrocarbons are low and your NOx is high.

 

[hawkeye18]

Almost;
hydrocarbons = running rich
NOx = running lean

cats usually burn out when you run rich for a long time... the unburned fuel causes the cats to get extremely hot and they cease to function when the catalysts burn out. If you run too rich or burn oil you get carbon which will plug the cats.

normally when all is well the catalytic converters heat up and burn off extra unburned fuel reducing hydrocarbons.

Couple things to try / consider:

-old o2 sensors (replace with motorcraft; supposed to be replaced every 60-80k miles)

-sticking piston rings (attempt seafoam or similar treatment)

-spark plugs &/or wires (worn or improper gap)

-dirty MAF (inaccurate metering of air)

-thermostat (does your temp gauge function? if not thermostat might be sticking open)

-vacuum leaks (causes un-metered air to enter screwing up ECM calculated air fuel ratios)



Use the SPOUT if your hydrocarbons are low and your NOx is high.

Or put a clamp on the fuel line and pull the spout! I think that's what they call "ghetto-rigging" lol

 

[badcamelot]

Had a nightmare of a time getting the last **** nut off. But split it with a chisel. Anyway, put the other cats on and while I was doing that I replace the valve cover gaskets which required removing the intake etc. A number of things had to be unplugged and Im quite certain all is plugged back in. Drove the car to the shop to run IM with spout out - but shop has no power due to construction, but driving back home the check engine light came on. My code reader says 10 176 and 452. One is O2 sensors, I know I plugged them both back in (they were new 23K ago) but didnt get that click feeling, so I will check to be sure they havent become unhooked. The other codes are for speed sensor and cylinder imbalance (according to the readers book) So, at this point Im either ready to go insane and commit crimes no one should ever utter or find a really dark deep hole and just jump in.