Hi everyone, I'm new to this forum.

I will drive nothing but a Ford but this 85 is killing me. Bought it 3 yrs ago.
I have been failing emission tests for over a year now (bad HC and CO) and can't null it out. I have rebuilt the carb, new O2 sensor, new plugs, wires, cap, rotor, EGR valve, and had it checked for vacuum leaks (non found)... I checked the temp on my cat input and output and they're the same. It seems the out should be a lot hotter than the in right? Took it to my muffler guys and they said the cat is bad also.

My question:
My tune tech guys checked they're book and said it was a single cat system with oxidation. When I research the cat I only find a single cat setup. My parts store can only find a single setup.

My muffler guy is the only one saying it's a dual setup but recommends a high flow single at more than twice the price. We're talking a $300 difference from a single oem type single cat setup.

I don't know who to believe and thought you might be able to help with an answer. I can find nothing on a placard anywhere. Sorry for the book and thanks for your time on this matter.
PS: Someone has removed the original exhaust and after the cat, installed a glass pack and brought the tailpipe out in front of the rear tire. Don't think this helps but thanks again...

Ray...
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Welcome to FTE. You didn't tell us much about your truck, but you may be able to figure out the answer here: Exhaust Systems - ???Gary's Garagemahal.

 

Hi Gary,
Thanks for the link, I'll check it out. My truck is just your basic 1985 F-150, 4.9L, single barrel inline six, 4 speed standard transmission, standard cab, 8' bed, not to pretty on the outside or in, but the body is straight and it runs like a top despite the almost 164,000 miles on it. Even the seats and windows are manual. It has AC that doesn't work so it's real hot in the summer. It is actually a good truck and I wouldn't hesitate to hook my camp trailer on and head for the mountains.

 

Where are you located? Better yet, is this a CA truck? If you look at the first drawing for the 300 in that link you'll see that only the CA trucks had dual cats. And, by the way, these drawings are from Ford's master parts catalog.

 

OK,
Went to link and it shows a single cat for 49 states and dual in Calif. Would a single cat bring my CO from 11.37 down to the 1.20 standard and my HC (PPM) from 476 down to a 220 standard? My Dilution CO+CO2(%) from 18.8 down to 6.0 standard? (That's @ 2500 RPM)
The CO(%) is actually better at idle(7.74) but the HC's and Dilution are even worse... I know, too many questions. I appreciate it though.

 

And no, not CA. I'm in Idaho...

 

It should. I say that because the truck was able to meet 49-state emissions with a single cat when new, so why wouldn't it now with a good cat? Yours obviously isn't working if the inlet and outlet temps are the same, so that would explain why you aren't making it now.

 

Thanks Gary for your help. I will discuss this with my muffler shop. I think they are just up selling for more profit. When they quote you one price, then try to charge you more for a system you don't need when you show up, seems dishonest and I should find a different shop. I really appreciate your time...
Thanks again, Ray...

 

No prob. If you can find the calibration code on the engine I can verify if it is a 49-state or a CA vehicle. Calibration codes are explained here: EGR Valves - ???Gary's Garagemahal.

 

Actually, your dilution reading is fine. HC and CO need to be below their respective limits. Dilution needs to be above.

Dilution is a quality check of the sample. The sniffer needs to see at least a certain amount of combustion byproduct in the exhaust. If not, that means a big exhaust leak or the probe isn't inserted far enough (watch it!). Either way, if the dilution value is low, the probe is drawing in too much "clean" ambient air and not enough "dirty" exhaust.

Years ago, I snuck several wrecks through emissions testing by nonchalantly standing on the hose. Once the standards included a dilution value, the gig was up for me.

I'm kinda curious how your truck is failing so badly. I took my '84 F250 351W through emissions testing today with no problem. This is a non-catalyst vehicle, with a tired old engine. Looks like my non-cat truck would have met the later standards for your truck:

 

So, KR, there are probably other things that need doing? In addition to the cat?

 

Hi Gary,
I can't seem to find the calibration code on my engine. Looks like the cover has been repainted so it was probably blasted or sanded down prior to that. Is there any other place to find it?

And thanks KR,
I would have to ask the same question as Gary. I know my timing is probably a little off as I am having difficulty with the timing mark on the balancer. But the numbers haven't changed much since I tried to check and set timing.

 

Your muffler guy is probably looking at a similar pic that I'm looking at here:

4.9L (300 I-6): 1980/89 Ford Light Truck Parts Catalog ~ 1980/83 F100 Regular Cab & 1980/86 F150/350 Regular & Super Cab (Illustration Section 52.2, page 3).

Pic shows two converters, but when you look up the application (1985 F150 - Parts List #122) in the Text (Section 52.1, page 6), only one converter is listed.

And, there's no mention of California and/or Canada only, so the application is all 50 states & Canada.

Parts List #122 also applies to 1986 F150 4.9L

 

Well, another tell-tale is the sticker on the radiator support that should say "49-State Emissions". Assuming it is still there. If not, we will have to assume it is a 49-state truck and not one that was brought in from CA.

Oh, another way to tell is on the certification label on the driver's door: Certification Label - ???Gary's Garagemahal. From that you may see a DSO (District Sales Office) code and can tell if it was ordered into Seattle.

 

Bill - That's the page on my web site and there are four applications depicted on mine:

1. 1980 6 CYL. CALIF. ONLY
2. 6 CYL. 300 w/ CONVERTER . 49 STATES
3. 6 CYL. W/O CONVERTER
4. 1981/ 6 CYL. CALIF. ONLY

His should be the second one.