Failed smog test

Hi guys, I haven't been on here in a while but I am needing some help here. I took my car in to get it inspected and it failed smog test. The hc's were high. I think the norm is under 100ppm and I was at 300ppm on low and high speed test. I have replaced spark plugs, writes, O2 sensor and the cat is only 1 1/2 years old. I also checked my egr and it seems to be working. I cleared my codes to see if anything new comes up. I have also removed my charcoal canister to get more room in the engine bay but that shouldn't effect the test right? I've tried to give all the info I've got. Please help. Also it's a 94 with 180k on it.

Strider

Put a bottle of heat in it and make sure it's warmed up really good before you take it in

Also if you have the timing bumped set it back to 10 deg.

Those after-market cats do not last all that long. I have one that I keep just for my annual smog test so I don't keep having to buy a new one.

Wouldn't a bad cat make me fail in other categories though?

Have you Seafoamed it yet? If not, search on here for tips. That did the trick for me.

NAPA sells "Guaranteed to Pass" for $15. I used it once on a friend's beater that had failed, and it passed. Make sure to get the car good and warm prior to the retest.

Ok, thanks guys. I'll try those suggestions and try it again

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Originally Posted by Strider

Wouldn't a bad cat make me fail in other categories though?

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Can't say. I was just suggesting that you might not want to completely discount the cat just because it is 1.5 years old. Maybe try some of the snake oils and then buy a new cat if it still fails. If it still fails with the new cat, then pull it off and sell it for $20 less than you paid. People are always looking for cats around here.

Also, read the guarantee on Guarantee to Pass very closely. It is not likely you will get any guarantee if it fails. That is not to say it does not work.

Make sure it's smoking hot before you have it inspected. Go drive the piss out of it, then head to the inspection station.

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Originally Posted by sammm

Make sure it's smoking hot before you have it inspected. Go drive the piss out of it, then head to the inspection station.

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This ^^^

Mine failed the first round because it wasnt warmed up enough. They drove it around the block a few times (after already warmed up) and it passed with flying colors.

This could be true because I just drive it half a mile to get inspected

Yep. The cat has to be above 700 deg F (or something like that) to be fully effective. That's why newer cars have the pre-cats close to head - better emissions during engine warm-up. Go flog it for a bit, then come screeching into the inspection place all Dukes of Hazzard style.

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Originally Posted by OZMDD

Go flog it for a bit, then come screeching into the inspection place all Dukes of Hazzard style.

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And hope there is not a long wait.

With a stock exhaust, mine barely passed nOX last year. With a full exhaust this year, it should be interesting to see what happens. Sucks to have to take the time to set up the machine though, the car cools down a lot just sitting there while you strap it down and try to find a spot where the shitty inductive RPM detector won't read half or twice the RPM's it's supposed to etc etc. Dyno states are a pain in the ass. Luckily they pay .8 instead of .5 hours.

So I decided to go ahead and pull my injectors and clean them up first. Then sea foam it and try and pass

That's one idea. Can't hurt, but I'd have tried the cheap fix to get my sticker, then worried about injectors at my leisure. Good luck!

So I did a compression test Here is what I got cyl 1=130, 2=100, 3=65, 4=140. So I added oil to #3 and it went up to 75 psi. Think it's my valves or valve guide? Can I change them without pulling the motor? Live in an appartment. :-/

Those are very low numbers. Time for a rebuild. You should be seeing 175-180 all the way across.

BTW, Make sure when you do the compression test, have it at WOT and crank it about 7 times.

Yeah, let's make sure you did the compression test correctly.

1. Start with a warmed up engine.
2. Unplug the connector from the CAS. That way you're not spraying fuel or trying to spark the plugs.
3. Remove all of your spark plugs. Relieves compression load from the starter.
4. Put tester into 1 spark plug hole at a time.
5. Floor the accelerator pedal and crank at least 6-7 time.
6. Repeat for all 4 cylinders.

Do the above, and let's see what we have.

BTW, high HCs means that you're running rich. A cold engine will normally run rich (kind of has to).

Those numbers can't be right. Either your gauge is off or you've gotten something wrong. Valve guides can be changed in the car, but they don't have anything to do with compression. They can sometimes leak a small amount of oil onto the valves which causes a !little smoking. Compression issues are either bad rings, bad/burned valves (not seating correctly) or something much worse. Valve guides are the least of your worries if those numbers are right. Consider comparing your valve to another good engine, or try a different gauge. Its also a good ideas to hold the throttle butterfly open to get plenty of air.

A compression test is not rocket science. The key is # 4 140, #3 65. Number 4 cylinder has over twice the compression as number 3. This means number 3 is bad period. Open or close the throttle, warm the engine, cool the engine, squirt oil in the plug holes, do whatever you want to do. The fact is number 3 is is bad.

Good point. I also read people saying to do it with a warmed up engine but the spark plugs will probably get stripped trying to pull them out at that point. So I'm saving up for a used motor. :-)

Rebuilding a motor is a fantastic learning experience, and is much simpler than most people assume. Since the motor already has issues, you can't really ruin it at this point, and you could save yourself a significant chunk of change in the process. Pul the head, have it decked, cleaned and refreshed at a machine shop for a couple hundred bucks (valve job, seals, possible springs), replace the rings (tools are cheap at HF), replace all the seals and gaskets, WP, timing belt, reassemble and rock on.

You should probably check #3 piston while you are in there.