Old mustang & emissions inspection

Hi, I am trying to help my niece, her dad gave her his '86 Mustang but we have to get it to pass emissions inspection in NJ. Her dad gave me some advice about borrowing a part from another Mustang to get it through the emissions test but I really don’t know anyone to borrow it from. Can anyone recommend what needs to be done to get it to pass inspections? It failed last week, we have a couple weeks to fix it. Thank you. ps it has a dual exhaust system. He used to race it.

Does it have the catalytic converter(s)? You may need to get a mechanic involved, this could end up costing some significant $$.

Is there something wrong with it now that it doesn’t meet its 1986 specs ?

The emissions testing people are supposed to know the difference in vehicle specs and test accordingly.

My brother in law says yes right now it has 2, but stock is 4. My understanding is that emissions requirements have become more stringent since this car was built, so I assume that is why it failed. I mean it runs fine.

Yes I will definitely be using a mechanic! I don’t know how to do this stuff. the trouble is I don’t even know what to ask the mechanic to do.

Typically the emissions requirements are based on the car’s year, so it should only have to meet '86 requirements. It’s been modified, so that may be the problem. Ask your BIL what parts he thought needed to be ‘borrowed’.

And it’s the mechanic’s job to figure out what the problem is, but he needs to be one you trust - do you have one?

My brother in law said this “maybe a stock-h pipe with the 4 cats may work” does that mean we would need to buy 2 more cats? I have a good mechanic in my town but if you want to recommend someone who works on Mustangs in North jersey I’m all ears.

I can’t imagine where you’d find a replacement exhaust system to borrow! I’d have your mechanic take a look, see what he says, you may well have to pay him something to diagnose this.

I don’t think anyone can tell you what to do because no one knows what’s missing or why it failed emissions.

It sounds like a GT with the 5.0 so dual exhaust would be normal. You state that he used to race it. If he used to race it this means that if the engine has been modified it will never pass emissions.

These cars were SEFI injected and if it’s been converted to carburetion (common), the camshaft changed (also common), and so on then there will have to be a lot of work and money involved to make it a street legal, emissions passing car again.

You might find out exactly what has been done to that car and post back. It’s also possible that if the car has been thrashed on the race track and is an oil consumer it will never pass no matter what; short of a new engine.

ok. thank you. I have no problem paying for a diagnosis. just wanted to see if you guys had any thoughts. i appreciate it.

Exactly what failed and what were the readings?
How many miles does this have on it?
Is it using oil?

Give us a bit of information to work with.

I have the report at home, I’ll have to write more later. It uses oil quite a bit. it has more than 145,000 miles on it. odometer no longer works. sorry to not have all the info. I will repost when I have more. i appreciate the help.

We understand, no problem. But it’s starting to sound like a ‘can’t get there from here’ situation, with lots of problems compounded by lots of modifications. I bet 5 minutes with your mechanic might bring everything into focus…

I got my emissions cert last year for the fun of it. Your vehicle will fail immediately if any of the factory HW is missing…they will fail it upon the visual checks by default. LEt us know EXACTLY what the BIL says it needs…what part are we talking about. The vehicle only needs to meet 86’ spec…but as soon as you remove any factory HW…it fails the visual test and never makes it to the actual emissions real world check…which it very well may pass.

You either may wind up spending a fortune on getting it into spec…or find a not so straight and narrow…to grease to “help” you pass…happens all the time…

Seems like the donor is zeroing in on the exhaust system. I would go to a good muffler shop. They can tell you if the cats needs to be added and if the ones you currently have on there are bad.

Slow down folks. Let’s get the readings first. The OP has already responded that the engine uses quite a bit of oil. That alone could easily be the source of high HC or high NOx, but one would be directly from the oil burning and the other from comtamination of the cat converter.

First the readings. Without those, we’re all just guessing wildly.

The '80’s cars are emissions nightmares…You are on a path where you could spend more money than this car is worth…

Did it fail a VISUAL inspection, parts missing or modified…Or did it fail a TAILPIPE test, where the actual measure emissions are too high? Or did it fail BOTH…??

A look at the NJ emissions program shows that pre-96 cars go through the sniffer on the tailpipe test.

Before considering spending beaucoup money on rebuilding an exhaust system you need to consider the oil burning problem because that will shoot the HCs through the roof and any NOX related problem with the converters or O2 sensors would almost be irrelevant.

This car sounds like a bear.

You probably have low compression - probably bad rings.
low compression inhibits fuel burn. It also lowers your horepower.
Simple solution - USE THICKER OIL. it may be bad for the engine in the long run - but REALISTICLY how long do plan on putting a quart a (increasingly short time here) in it.

This burning oil also fouls spark plugs. Find someone who sells them by the shovelfull. My theroy on spark plugs are COPPER + flattest boxiest electrodes are best. Gap them right - there is a tool for this.

if you have a catalytic converter - YOU WILL KILL THE CAT WITH ALL OF THE OIL YOU ARE BURNING. add 2 more? they will die as well. You need to fix this oil burning problem first.

Maybe this is a crate motor job. A crate motor with EFI and oxygen sensors and a catalytic converter. It wont burn oil. It will very likely pass e-check. It will make more than 95 horsepower. (try 300h.p. - for a not too spendy v-8) (or heck go nuts and get a crate motor that you can safely turbocharge - and reach for 500+)

Of course this spunky new crate motor will probably shred the old transmission in about 6 months. Unless the person you got it from built it up a little. But thats another post for another day.

Option #2 is a rebuild. But for my time and money - I like new parts. Unless there is some historical value to the car where keeping the engine # matching the body# - new parts.