danglerb

This is the 85 Euro I initially purchased to part out, but went soft on. It had the valve damage from a broken timing belt that some claim it can't have, and I sold the engine as a core before the car was delivered. Once I saw it, the 195K miles, poor paint, rough rough interior charmed its way into my heart, so I swapped the engine out of my 84 Euro parts car into it, and it passed smog and got parked waiting on some suspension work and time to do it. Two years later it passed smog again, got parked again, but driven frequently enough to keep out possums, but not to use up a tank of gas when due for smog again now.

Gas is maybe more than a year old. It will get drained on Monday, if not sooner (anybody local have a rental car that needs gas?)

First smog test, which I do intend to dig out of my files was as I recall "fine" except for very high, but passing NO. Prior to second smog test I put in a rebuilt MAF from Injection Labs, and I don't recall the details, but it passed.

As mentioned several brains, NOTHING related to federalizing was left in it. Euro brain ran fine, but not sure I used it even during first smog test, switching to a US 85 brain with special fuel tables for the Euro motor. This was running with an OLD MAF. Brains are sitting on the passenger floor and CE panel is open due to messing around with it being my most recent actions. Until I take a close look I can't be sure of status on any of it.

Topside inspection I hope to get to this weekend, but won't be able to put it in the air til Monday.

Ah well, its now gone from a crisis in my mind to an adventure, so I plan to try and enjoy it and not worry about any downside until it really happens.

Rich9928p

The smog tests tell you that your engine is not running properly. If there were no tests, many car would have many undiagnosed problems.

Some federalized Euro cars use external boxes that use an O2 sensor, but are wired to tweaks things like the coolant temperature signal to trick the module into changing air/fuel mixture.

To further Colin's advice, many owners of 1985 - 1986 US 928 and mechanics do not know that in order for the lambda and idle speed regulation to work properly, the base CO% (set at the MAF) and idle speed must be set. The procedure is in the factory workshop manual pgs 24-204 to 24-207.

1984 - 1986 Euro 928s require CO% setting at the MAF and 1987 and newer 928 have a POT down by the LH unit for CO% adjustment (it is not done at the MAF).

The CO% measurement must be taken before the CAT.

The 1987 and newer CAT equipped 928s do not require base CO% and idle speed regulation.

Rich
'93 GTS Cover girl
'87 S4
'79 5-speed
'79 Euro track beast

The Fixer

My '83 catalyst had 58k miles when removed,
if you can make it work you can have it. Very nice condition
and the car always passed 'smog' here in Pa. We call it emissions.
I'll never need it.
Pay shipping and i'll ship to you.

If Mike passes, the offer is good to whomever wants it including 928 International to resell.

danglerb

Thanks for all the offers and advice, some things I need to check and try before anything that needs welding, shipping exhaust parts only as a last resort, but I am thinking pretty hard about a factory dual cat setup "eventually", but only factory part being the two foot section with the cats.

WallyP

leperboy said, "However, many of us here are only driving our 928s a couple thousand miles a year."

This won't help you young scamps, but...

I don't know how many states have the same arrangement, but in Georgia you can avoid emission testing if you are 65 or older, and if your car is ten years old or older, and if you drive your car less than 5000 miles per year.

larryfish1

I would be vary wary of aftermarket converters. I work in the precious metal industry and the aftermarket guys buy whatever metal is cheapest. The three main metals being platinum, palladium and Rhodium. They switch around to save money. The OEM products are strictly controlled by the automakers. They use the same amount of each metal everything and do extensive testing to ensure the cat. preforms exactly the same every time and over the same lifespan. You may buy an aftermarket and it preforms well and the next batch not so much. I would only buy OEM cats.

GregBBRD

This has to be one of the best deals on the planet! I've been quietly buying these and sticking them onto my customer's cars that have "tired" cats.

danglerb

Found a post with my first smog test in 2008.

Emission test results.
15 mph 1484 rpm 15.2% CO2 0.5% O2
MAX...AVE...MEAS
120 ... 41 ... 33 HC ppm
0.76 __0.13 _ 0.06 CO%
1074 _399 _277 NO ppm

25 mph 1772 rpm 15.1% CO2 0.2% O2
MAX.....AVE...MEAS
95 ..... 29 ..... 28 HC ppm
0.56 ...0.11 ...0.03 CO%
904 ....332 ....891 NO ppm

Got nothing done over weekend, maybe do some today.

BC

What cat type is the car Mike? I have the Cats from an 85 US car sitting in the garage. Its the not-so-tru-duals

Imo000

The 85-86 converter and pipes are the same as the S4-up.

BC

They sure don't look the same.

danglerb

I found a pair of cats from an 85 yesterday, so I should be good to go. I currently have whatever the official Magnaflow replacement cat was from just before the Calif catalog went into effect. Part of my dig through old records plan is to locate receipt and details on that cat as well as smog test between one just posted and now.

85+ I think are all TWC dual cats, but I seem to recall some looked a bit different from others, but two physically separate cats, not the two in type from aftermarket.

I'll try to take some picts when I mess with it tomorrow.

danglerb

Update

Drained the old gas, put in 5 gallons of fresh, bottle of Techron the new concentrate plus, picked up a one day moving permit from AAA, and romped up and down the freeway a bit.

Car is idling smooth, and running great, but not pass a smog test great.

Greg has a nifty new Snapon 5 gas meter, but adjusting MAF made only a tiny improvement.

Disconnect the O2 sensor and HC and CO improved without adjustment, but not a lot.

Tried a new O2 sensor, no change.
Tried a new USA brain, worse, with some wiggle.

Best current guess is that 1/4 and 5/8 injectors have a flow mismatch. Current headpipes have one O2 sensor in 1/4 side. Factory US 85/86 dual cats have the O2 in the balance tube.

Plan for the morning is to get factory US 85/86 dual cats installed and check the gases again.

Another thought is to pull the injectors and look for one with a bad flow/pattern and replace it, or send them all out for cleaning, but I really would like to get past smog and then do an injector update to a modern style with a rail clip.

danglerb

Old car PITA, exhaust guy shines his flashlight in the rear pipes of both sets of dual factory cats I bought, one is just gone, bits of cat biscuit around the edges of the pipe, another biscuit is cracked making a tinkle sound when moved, other set tinkles as well.

Same day, two different "experts" chewed me out claiming the opposite of each other, OBDII cats are great, old factory cats are great, vs they are junk depending on person. Naturally I took both expert opinions under consideration and did something else, bought a pair of Magnaflow 36304 CARB Calif approved cats for 90-95 928. I figure "maybe" if it comes down to it they will pass the visual, last time the guy had no interest in crawling under the car. Five star reviews on Amazon that they work great, only one four star griping they required welding, but worked great. One guy reported they reduced some emissions to zero and smog guy wanted to check them out to see how that happened.

Updated and revised plan for Monday ...

Have exhaust guys hook back up exhaust that was on the car adding a o2 bung at the y merge in front of the single magnaflow 9004 so I can drive it until new cats arrive from Amazon, as well as pull injectors and send off to Witchhunter and try to set CO% before potentially messing up new cats.

Have the exhaust guys fabricate the 2.25" adapter to use factory dual cats with 85/86 manifold on a 16v car. This in case I "can" tune in the CO, but doesn't pass visual.

When the 36304 cats arrive have them fabricate new system from manifolds back that roughly looks like factory dual cats.