Catalytic Converter for California SVO's - Selection and CARB Testing

[EVO SVO]

As part of a complete Federally mandated emission system, every SVO was factory equipped with a catalytic converter. And as well-known to all auto enthusiast, California has always held its cars to its own higher level of emission certification than the rest of the nation. Those two levels of standards make the selection of a catalytic converter (CAT) more complicated and costly than it needs to be.
I summed up my experiences, along with the data gathered during this process. Please note this write up is from my personal experience and not an endorsement, instructions or interpretation of any Federal, State of California or local legal requirements or codes that have jurisdiction over emission standards or catalytic converter requirements. To make this as fact based as possible, presented are screen captures from the official California Air Resources Board (CARB) and manufactures websites. In total, a lengthy presentation in an effort to capture current information for 1984 through 1986 SVO's. Hopefully those in my predicament will reference this and for the others, just another boring bedtime reading.

Executive Summary:

1. Federally approved catalytic converters from another state are not legal in California unless it has a CARB Executive Order number.
2. All SVO’s in California must have a 3-Way converter (TWC). While the use of 2-Way converters ended in 1981, they are still being sold outside of California.
3. The CARB Executive Order numbers shown group our engines with other 2.3l engines. Because this is how our CAT certification paperwork was submitted and approved by CARB. It is possible somewhere in the literally tens of thousands of pages of listings, there is a CAT that is specifically listed for our engines. The Turbo-TBirds are also listed with this generic 2.3l engine. I could not find anything that would lead me into believing that a ‘unique’ CARB catalytic converter only for the 1984, 1985, 1985.5 and 1986 SVO Turbo engines exist.

Installation: the new CARB catalytic converter.

1. The existing exhaust WAS a 3” I.D. stainless steel down pipe into a 3” I.D. stainless steel x 4” diameter x 9” long CAT, splitting into a 2-1/2” dual stainless steel Magnaflow mufflered exhaust system.
2. The approved replacement CAT was a walker #81122 aluminized steel CARB legal unit with a (measured) 2-1/8” I.D. inlet/outlet. The manufacturers data says 2-1/4” I.D.
3. On the phone when the muffler shop asked me if it was “stock”, of course I said “Yes”, thinking they meant “do you want a stock CARB CAT”. Quoted cost was $550 – installed, for a direct replacement into a factory “stock” exhaust system.
4. When they put it up on the lift, we looked at the existing 3” stainless steel system. The first words out of their mouth was – “3 inch stainless steel was factory?”.
5. After lots of cutting, bending, flaring, adapters and welding (no cussing haha) to make it fit the 3” system, we agreed on an extra $100 cash to cover the additional 50 minutes time and person.

Driving: Impression to dyno testing

1. The SVO started and had a rougher idle with an intermittent cough (mis-fire ?).
2. Idle dropped about 50RPM
3. Previously the smog tester told me to get the exhaust system completely hot when bring it into the dyno bay. No cool down. The CAT does not work well cold or just warm. Internal temps should be at 500F+.

Testing: Getting certified CARB legal

1. Fortunately, my testing center had a well known reputation for its certification work on high priced European performance cars and old Detroit iron.
2. Wanting to get a “before / after” status of the SVO, the testing center ran an unofficial ‘before’ on the existing CAT wheel dyno test without a CARB submittal to avoid a “fail” on the SVO’s CA records. The SVO was almost good on everything except the deceleration hydro-carbons were a factory of 5 too high. Yikes !
3. After the new CARB CAT, the SVO was put on the dyno rollers - Hot and ready. Checking the timing, idle and all the other required emission equipment, the testing proceeded. This is nothing like a wheeled dyno power pull test session, but just as heart stopping for me.
4. After the installation of the new CAT, the SVO passed the dyno portions. They alerted me that there was most likely an air leak after the mass air flow sensor because the NO’s level were high compared to the low level of hydo-carbons. He felt this was most likely due a leak. Great info.
5. The fuel tank cap sealing, and fuel evap recycle was the portion that failed the first test. After they fussed with the testing pressure and sealing, they got the online computer to say “Passed” on this test.
6. After a few minutes of mouse clicks and staring. the CARB online program displayed “PASSED”. Hallelujah, wonders of the world never cease !
7. A side note – on the first unofficial “testing”, the emission tester noted that I had an unapproved fuel pressure regulator. Can’t hide its beautiful anodized red body. But I took it back for the second ‘official’ test with it still installed. He saw that it was still installed, I explained that for time and cost reasons I did not change it, but could come back later with a CARB legal one. He just smiled and waved me away – “PASSED”.
8. Total for the smog test was $110.00 which included the paper certificate, low pressure fuel evaporative test and electronic transmittal fee for sending the test results to the state. And to show my gratitude for the little extra help, I delivered an 8oz box of SoCAL’s famous See’s Chocolate Truffles for the wife working the test station counter ($17.00).

Epilogue – Driving legal

1. The prep for the testing included new Autolite Copper 104 plugs ($17.47) (replacing the NGK R ‘TR6’), Standard Co. Distributor Cap FD159 copper terminals ($29.55), 6qt. Mobil 5w-30 (Costco), WIX 51068 oil filter ($14.22), clean and re-oil the K&N air filter, and a fresh pressure wash at the local manual car wash ($6.00). Note, the plug wires were new 8.5mm.
2. After getting the CARB legal CAT and passing the emission testing, I was now ready to face the California Department of Vehicles (DMV) with temp title, temp plates, insurance and emission testing certificates. Of course the typical DMV check for the physical vs paper VIN match ups, window tints, ride heights, tires etc. I don’t think there are any DMV registration laws about political bumper stickers - yet HaHa.
3. DMV Registration Cost - $1,301 to register the out of state 1986 SVO, meant taco truck food for the next couple of months.
4. Performance – after several full throttle freeway acceleration runs (of course, always obeying and following CA state motor vehicle laws), what was an exhilarating acceleration ride in 3^rd gear from 3,000-6,000 RPM was now a slow and steady climb from 4,500 to 5,500+RPM. Before the CARB CAT, pushing full throttle, the tach needle would swing fast from 3,000 RPM up without time to really watch it before grabbing 4^th gear at 6,000RPM. Now with the new CAT, I can get out the popcorn at 5,000RPM+ and watch the tach struggle to go higher as the intercooled 2.3l turbo was losing it’s momentum to rev higher. Really sad.
5. The new CARB CAT has changed the performance (for the worst) of the engine. Must now up shift on any driving situation under 2,500RPM.
6. Mileage has also gone down. From a highway 25 - 27MPG to somewhere around 22-23.
7. The idle now has a definite mis-fire at idle.

The test results:
2024_06-05 Pasadena Test Only Smog Check-final.jpg

[EVO SVO]

Official FORD manual diagram of the 1986 dual exhaust system. Show this to the smog tester if they question your stock dual system. CARB listing shows only a single exhaust system. See the attached CARB executive orders for more details.
Catalitic converter -400.jpg
Ford Shop Manual - Cover.jpg

[EVO SVO]

Screen captures from California's CARB official Aftermarket Catalytic Converter Database
ACCD page1.jpg
ACCD page 2.jpg

ACCD page 3.jpg

[EVO SVO]

Stock direct replacement type CARB CAT. Walker 81122.

Catalitic converter.jpg
catalytic_converter_3way_cutaway_1-4073932199.jpg


Offical CARB Executive Order D-182-65 allowing the use of the Walker CAT inlieu of a FORD OEM CAT.
Luv condition #7 haha
Exec D182-65 Walker1.jpg
Exec D182-65 Walker2.jpg
Exec D182-65 Walker3.jpg
Exec D182-65 Walker4.jpg
Exec D182-65 Walker5.png

[EVO SVO]

A comparison of the old 3" CAT inlet diameter vs the new certified CARB legal 2.125"
3 inch CAT.jpg

[EVO SVO]

3-way-converter-e1661199535214.png




Official CARB Executive Order D-193-150 allowing the use of the Car Sound Exhaust Systems, Inc.(Maganflow) CAT inlieu of a FORD OEM CAT.
Luv condition #7 haha
Exec D193-150 Magnaflow1.png Exec D193-150 Magnaflow2.png Exec D193-150 Magnaflow3.png

Exec D193-150 Magnaflow4.jpg
Exec D193-150 Magnaflow5.png
Exec D193-150 Magnaflow6.png





Magnaflow Catalytic D-195-150 or 3322306.jpg Screenshot 2024-07-18 111957b.png

[EVO SVO]

Some unofficial web info
CA vs other.jpg

[MRains]

Thanks so much for documenting your Smog Check adventure in California. It was personally helpful in adding more clarity to the process.

Some background: My 86 SVO was bone-stock when I bought it in 1992, I recently moved back to California and am in the process of registering the car, which includes the mandatory visual inspection and emissions test. The original catalyst and exhaust system are long gone.

One minor clarification: You mentioned the smog check technician suggesting a possible air leak "after the mass flow sensor". The SVO (and other Ford-family offerings with the fuel injected Lima) came with a VAM (Vane Airflow Meter), which is an earlier Bosch system and a very different animal.

Additionally, CARB Executive Orders (EO) which apply to other catalyst manufacturers (e.g. D-182-65 listed above for Walker catalysts) show the converter type as TWC (Three-way Cat) + OC (oxidizing catalyst). From my research OC implies air-injection, which would apply to the V8 cars but NOT the SVO. In other words, some of these EO tables are incorrect.

Finally, the EO listings do show all the applicable 4-cylinder Mustangs as single-exhaust. My understanding is that CARB isn't concerned with the items after the catalyst, which is why cat-back systems don't require an EO. Put another way, it shouldn't matter whether your car had an early single or later dual exhaust system.

Part of me hopes the process is easy, and part of me wants to do battle with the State over these obsolete vehicle smog requirements. I'll try and remember to post the outcome.