High HC, need second opinion

boomienutcake

New Member
Mar 6, 2008
28
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0
Tucson, AZ
Hi guys,

I'm having a hard time with emissions again (posted for problems last year as well)...time really seems to fly by!

This time I'm not having high CO readings AT ALL, limit is %1.20, I'm coming out at %0.55. Hydrocarbons are soaring in the mid-high range though...loaded is coming up at about 170, idle way up at about 329, limit is 220.

These results are from second test (have to pay for third now!). First readings came out loaded 191, idle 380. I ran a test on my O2 sensor, found numbers all out of whack at closed loop, .4 and less voltage under load (lean), so I grabbed a new one and threw that in hoping it would patch me up...no go, but did bring numbers down quite a bit. Haven't tested new numbers, but I feel new sensor helped considering the second test's numbers.

Grabbed a can of starting fluid and started spraying around (minimal, no worries of explosion!), and found two vacuum leaks:

One of them was coming from the large inspection hole cover from the top of the intake runner, so I pulled, applied small amount of black RTV gasket maker and re-sealed (no money OR time for actual gasket), so that should be go from this point.

The second leak is coming from the large vacuum hose that runs from the throttle body over to the ISC valve (the fattest one). I'm positive it's a split from the TB end, since I patched it a couple of years ago with some tape.

Now...I can certainly take the time to fiddle with it and get it sealed up, but I'm wondering if I take the time to do so, could this tiny leak be throwing off the O2 sensor enough to spit me to a lean condition, or could there be something more? Should I risk one of my new tests on just this one leak, and possibly fail yet again? I'm sure both leaks combined would cause some damage, and one is now fixed. I'm ruling out spark plugs (tiny bit of white from lean condition), plug wires, rotor cap, coil, etc. from this point. Also, no foul smells from tailpipe.

As a side note, I finally beat my way through last year by tweaking the AFM adjustment screw about 1/4 turn, ALL numbers were failing, CO probably around %3.4. New AFM has been installed since.

Need any info ASAP, must pass by tomorrow!!!!

Thanks!
 

90T04

New Member
Mar 30, 2005
279
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41
Tucson, AZ
www.azsupras.com
High Hydrocarbons are from raw unburnt fuel in the exhaust. I would verify the integrity of the ignition system first.

Edit: Sorry, Just read that you had checked your spark plugs and your entire ignition system already. Its possible that you could be getting a lean misfire, make sure all vacuum leaks are fixed before you take it back through. Have you pulled codes on it yet?
 
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87tomanymods

87tomanymods
Oct 25, 2008
193
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0
lansdale
www.myspace.com
def take care of any leaks first but also .i would run a slow water drip just after the tb then go blow the carbon out . and the stp super concentrated fuel cleaner does wonders. if all else fails a new stock cat usualy does the trick for hc's