Colorado Emissions, new info, and new questions about the AFM Also an error in the FSM! (1 Viewer)

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Joined
Mar 21, 2015
Threads
29
Messages
380
Location
Parker, CO
I have been battling Colorado emissions for months now, and as a result my 94 has been sitting in the driveway.

I purchased a set of magna-flow cats and had a local shop add flanges to make them bolt right up in place of the old cats. The shop did a good job and I gained almost 2 inches of ground clearance under the cats. Everything was great until I got to the testing location in Parker.

Immediately I noticed the inspector taking a long time to look at my cats, then reading the emissions equipment label under my hood. Then he had another guy looking, then the manager came over and was looking as well. :censor:

They pulled my rig out without even testing it, and the manager summoned me over. He informed me that my cats were wrong. He showed me the sticker and told me that I needed 2 "Three way cats". I informed him that I had 2 three way cats. Brand new ones in fact. We proceeded to argue in the parking lot for 10 minutes, it became very obvious that he didn't know what he was talking about. He gave me the number to a state office, and told me I could get a state inspection there and they would determine if my cats were kosher or not. I left the facility and immediately called the number.

I was connected with a fellow named Loyd (I think) and I explained the situation. He asked me if my cats "Looked like glass packs". I told him that they look exactly like glass packs. He said that must be the source of the confusion. He then informed me that "If you got some magnaflows or something, I can guarantee that they aren't EPA certified, and they will not be legal to use". I knew they were EPA certified when I bought them, so I just made an appointment to get them checked at the Technical inspection facility in Highlands ranch.

Luck would have it that I got a appointment same day.

I met a inspector at the state inspection station who was very knowledgeable and helpful. He took my cruiser into his bay for over an hour, I was very concerned at first because I just thought he was going to check out my aftermarket cats, but about 45 minutes into my wait I heard the unmistakable sound of duratracs on a dyno and I relaxed.

He came out and gave me a wealth of information. Mark is not your run of the mill emissions "expert" who was fired from 3 different McDonalds before finding his true calling. He has decades of experience working for a independent shop before taking his state job. The first thing he told me was that 80's are some of the most problematic cars in Colorado, especially the OBDI variants. He assured me that it was a great vehicle, but they just don't get along with Colorado emissions standards.

Mark did a full diagnostic on my truck. He determined that my O2 sensors were not the problem, and he ran my truck on the dyno and found it to be over the limit on NOX and CO. He told me that it was running rich and that he thought the AFM was to blame. He even described to me in detail how the trap door AFM works, and that there was a way to internally adjust it. His official advice was to find a good independent Toyota shop and have them adjust the AFM.

This was the first I had heard about the AFM being adjustable, so I came home and did some searching. I performed the on vehicle test of the AFM according to the FSM, and it passed. I then removed the AFM (DON'T REMOVE THE TWO SCREWS) and did the off vehicle test. I initially thought it was failing the off vehicle test, so I decided to open the unit up and have a look at the guts. I did so by cutting the silicone seal around the cap and prying it off. Everything inside looked fine so I studied the FSM again. That is when I discovered that the FSM has a error in it. Look at these 2 pages. Notice that the pinouts don't match!:bang:.

So If I test it using the pinout diagram from the first page to identify "E2" and "VS" then the ohms change as I move the flap, and the readings I get are within spec.

I continue my research about the AFM and find this guide for adjusting it. Looks easy enough so I give it 2 clicks in the lean direction. I put everything back together and used electrical tape to seal up the AFM temporarily until I can get it to the test center again.


So I wanted to ask some the guru's on here if Marks advice holds water. It makes sense to me that the spring in the AFM would wear out over time resulting the AFM reporting a higher volume of air than what the engine was getting. The follow up emissions test will be the real tell, but I won't be able to get it in for a full week.

Other things I already did recently in my emissions saga: Replace cap and rotor, plugs and wires. Replace EGR modulator and several shady looking vacuum lines. None of these items effected my emissions readings, and neither did replacing my cat's :doh:.
 
They may fail you on the visual inspection due to opening the sealed cover. Tape is a dead give away and even fresh RTV is pretty easy to identify. I have heard that the air bypass adjustment screw MAY have the plug drilled out so it can be adjusted to increase or decrease the bypass flow. It was probably just a rumor?
 
They may fail you on the visual inspection due to opening the sealed cover. Tape is a dead give away and even fresh RTV is pretty easy to identify. I have heard that the air bypass adjustment screw MAY have the plug drilled out so it can be adjusted to increase or decrease the bypass flow. It was probably just a rumor?


Air bypass screw? I'm going to have to read up on that.

From what I understand the visual inspection only applies to the emissions equipment. Since the AFM isn't specifically part of what's listed on the under hood sticker, they wouldn't care.
 
First of all in my experiance each emissions location is wildly different when it comes to the scrutiny in this state. Where did you go?

I had one cat on my rig and no PAIR and longmont emissions put it straight on the dyno after the visual, it failed due to bad O2 sensors. Same set up taken to boulder emissions 1 week later and it failled visual. Same setup taken to fort collins emissions and it passed visual.

So before going down a rabit hole I'd suggest just driving to the next emissions testing center and try again. Also found its good to be very friendly and talkative to the testers (you don't have to hang out in the booth), if they are receptive to your pleasantries they are generally more lax.

Secondly, did you check your timing? spark plugs or get your cat hot before you went in? You really should never have to adjust your AFM.
 
Wow, don't you just love the first state workers you ran into, who have the power to just up, and fail your truck for having the "wrong cats". I'm so glad to hear you finely got a hold of a state worker (Mark) who knew what he was doing, and who took the time to HELP you with your problem.

We use to have so many problems with our customers failing our state inspection program (IM 240). that i broke down and bought a 5 gas analyzer for our shop. With that gas tester we were able to pre test all our customers cars before they left for the test. To tell you how screwed up our state test sites were, I've had customer call me after being set up in my shop to pass the state inspection.

They would pull into one lane at the state inspection site, and fail, even though we had just used our 5 gas tester to set their car up to pass the test. Then they would pull out of that lane, turn right around, pull back into the facility without doing any adjustments to their car. But this time they would line up in a different test lane, and this time they would pass the emission test with flying colors.

The problem is, there's a lot of money to be made, so these sub contractors that do the emission testing for the state don't calibrate their equipment like they should. The way i look at it, they want you to fail, the more you fail, the more chances they have to make money off of you by doing retests.

Another little trick the test sites would do around here, they would run you through the whole test, great you passed the roller test. But oh no, your not done yet, now they would test your gas cap, and guess what, they said your gas cap failed. But wait it gets better, now when you return to the testing facility with your new gas cap, they say oh no, we can't just test your new gas cap, we have to have you perform the whole roller test over again too. This just gives them another chance to fail your car when it' on the rollers, to me, all this testing has just turned in to a big money making scam.
 
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Arizona got into the gas cap rat race a few years ago. Somebody caught on at the capital, and now if your cap fails, they have to give you a new one for free!! At least they got one thing right.
 
Wow, I sooooo hope Skagit county holds to its' roots of tulips, agriculture & dairy farms. We still have the HSC diesel at cardlock pumps if you know where to go.

Heck, you can drive a tractor on all but the I-5 corridor - you see tractors flinging mud all the time, and you have to dodge them come Autumn harvest. No exaggeration. It's oddly awesome.

No bogus tailpipe mafia with mechs or support shops kicking back to crooked state inspectors. Guessing this happens, IDK.

All the issues we have pale to that noise. A legion of minors with "glaucoma" & stoned parents of them is nothing, their gig.

Somebody better explain to the Penis.....err, Prius drivers their 'clean coal' is an oxymoron when they go all social justice / eco-freak warrior on our 80's.

And what exactly do they expect the battery they bought IN the Prius will do to the enviroment when they need to change it.

Ugh, cleary I'm in insomnia mode & sober - so less fun than a sticking locker.
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Tech: What is the best product besides the stuff @CycloSteve posted (was going to buy some for a buddy's 4Runner back @ Christmas, he's in King county / Seattle proper - they tailpipe) --- steve's stuff was some small batch stuff with a dead website. www._______104.com IIRC was his posted product.

So what is the best additive from all you seasoned tailpipe / CARB mandated folks?
 
Wow, don't you just love the first state workers you ran into, who have the power to just up, and fail your truck for having the "wrong cats". I'm so glad to hear you finely got a hold of a state worker (Mark) who knew what he was doing, and who took the time to HELP you with your problem.

We use to have so many problems with our customers failing our state inspection program (IM 240). that i broke down and bought a 5 gas analyzer for our shop. With that gas tester we were able to pre test all our customers cars before they left for the test. To tell you how screwed up our state test sites were, I've had customer call me after being set up in my shop to pass the state inspection.

They would pull into one lane at the state inspection site, and fail, even though we had just used our 5 gas tester to set their car up to pass the test. Then they would pull out of that lane, turn right around, pull back into the facility without doing any adjustments to their car. But this time they would line up in a different test lane, and this time they would pass the emission test with flying colors.

The problem is, there's a lot of money to be made, so these sub contractors that do the emission testing for the state don't calibrate their equipment like they should. The way i look at it, they want you to fail, the more you fail, the more chances they have to make money off of you by doing retests.

Another little trick the test sites would do around here, they would run you through the whole test, great you passed the roller test. But oh no, your not done yet, now they would test your gas cap, and guess what, they said your gas cap failed. But wait it gets better, now when you return to the testing facility with your new gas cap, they say oh no, we can't just test your new gas cap, we have to have you perform the whole roller test over again too. This just gives them another chance to fail you car when it' on the rollers, to me, all this testing has just turned in to a big money making scam.
South Carolina dropped its inspections due to exactly this condition.
 
This was the first I had heard about the AFM being adjustable, so I came home and did some searching. I performed the on vehicle test of the AFM according to the FSM, and it passed. I then removed the AFM (DON'T REMOVE THE TWO SCREWS) and did the off vehicle test. I initially thought it was failing the off vehicle test, so I decided to open the unit up and have a look at the guts. I did so by cutting the silicone seal around the cap and prying it off. Everything inside looked fine so I studied the FSM again. That is when I discovered that the FSM has a error in it. Look at these 2 pages. Notice that the pinouts don't match!:bang:.

I noticed this as well (and am having similar issues with my 93). If you ever need to test your IAC, note that there is a typo on that section as well when it comes to pin outs.

I just cut open my VAF and am making the changes you linked. Going to drive up to Fort Collins and back afterward and hit the emissions check before they close today at 1pm. Fingers crossed.
 
@DancesWithMutts I just passed by adjusting mine two notches leaner. Could not have done it without your post! Can see my troubles here.
 
Weird, I live in Golden and wasn't even aware they do a visual inspection. They throw it right on the dyno. Never open the hood or look underneath. Last time my pass window wouldn't open so they didn't even hook up the OBDII monitor. I go to the one by 58 and Ward.
 
yes, the one on ward and 58 is about 2 miles from my house. They usually just test the gas cap, throw it on the dyno and then you pass or you don't. if your magnaflow cats were EPA certified for your vehicle, you can provide the model numbers and that should squash any further discussion. I go with CARB cats since the warranty is usually better.
 
You mean it's not just a rumor?:cool:

Cannot tell if serious, but I have been looking for a solution for a few weeks now. And from looking at his posts @landtoy80 has been looking for one longer than me. I am just glad that it resolved my issue. No one has suggested "adjusting" the VAF in any other posts.
 
I've messed with afm's quite a bit. I always mark the original position before I make any change in case my adjustment makes it run worse. Then I don't forget weekly where it was at originally and can always put it back. May want to install a fresh O2 sensor as well sine the afm type fuel injection system isn't super alert to throwing a check engine light from poorly operating sensors. I would also bump up the timing 5 degrees.
 
Weird, I live in Golden and wasn't even aware they do a visual inspection. They throw it right on the dyno. Never open the hood or look underneath. Last time my pass window wouldn't open so they didn't even hook up the OBDII monitor. I go to the one by 58 and Ward.

The Adam's County station on 112th pretty much does it the exact same way.
 
All of these reports showcase that you shouldn't jump right into going overboard if you fail a visual in colorado. First go to a different testing location.
 
Looks like the OP is running an OBD I truck, but most of those claiming easy trips thru smog are in OBD II. Testinhg here in Az is way different between the two, don't know about Colorado.
 

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