Swap Emissions
Thread Starter
Teching In
Joined: Jul 2021
Posts: 9
Likes: 2
Swap Emissions I am very interested in doing an LS swap into an E90 using a kit. The kit looks really straightforward and makes wiring pretty simple by ripping out all the E90 computer stuff and replacing the stock GM ECU with a Holley Terminator. So the Holley website has the obligatory “not legal for street use” verbage. How real is that—or just a “please don’t sue us” disclaimer? I’m in Texas and need to pass inspection/emissions each year (this will be 100% my daily driver, not a race/track/drift car). Can you de-tune with the Holley and pass inspection? Has anyone passed inspection with a cat delete, or should I plan on keeping these? My plan is: aluminum block LS (III/IV, 6+L if findable/affordable, 5.3 if not), long tube headers, mild cam, LS6 intake, all hoping for breaking 400hp. I’m seeing videos of lots of LS swap cars on the road, so how are others handling emissions?
New info: So I asked a local shop and learned that they do an OBD2 scan, looking for vin and emissions equip (so I guess no cat delete). In aftermarket units like Holley, can you set up the vehicle’s vin? Anyone know what info an OBD2 scan would be looking for?
New info: So I asked a local shop and learned that they do an OBD2 scan, looking for vin and emissions equip (so I guess no cat delete). In aftermarket units like Holley, can you set up the vehicle’s vin? Anyone know what info an OBD2 scan would be looking for?
Last edited by GTIRoller; Jul 30, 2021 at 02:16 PM. Reason: More info
TECH Fanatic
Joined: Dec 2017
Posts: 1,467
Likes: 265
From: Bossier City, Louisiana
Hello,
Here in Louisiana, since I don't live in New Orleans or Baton Rouge, I don't have to worry about it. In Texas, if I were you and before I spend my first nickel on swap parts, I'd consult Texas emissions law. Go to your local tail pipe check station that you need to visit every year and ask them - these are the people on the spot with the information you need and I predict they will have some kind of a brochure for you to consult.
These are the people you will be working with and simply tell them up front what you wish to do. You don't mention what vehicle you are swapping into but it is quite possible that if it is old enough, it might be completely exempt.
Rick
Here in Louisiana, since I don't live in New Orleans or Baton Rouge, I don't have to worry about it. In Texas, if I were you and before I spend my first nickel on swap parts, I'd consult Texas emissions law. Go to your local tail pipe check station that you need to visit every year and ask them - these are the people on the spot with the information you need and I predict they will have some kind of a brochure for you to consult.
These are the people you will be working with and simply tell them up front what you wish to do. You don't mention what vehicle you are swapping into but it is quite possible that if it is old enough, it might be completely exempt.
Rick
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,615
From: Central Cal.
That's true even here in Commiefornia. Anything older than 1975 (first year of catalytic converters...) is off the hook. And if OBDII, they just do a visual for needed equipment and hook up to the OBD plug to check for codes. No sniffer involved...
TECH Resident
Joined: Apr 2007
Posts: 866
Likes: 218
From: Montgomery (Lake Conroe,) TX north of Houston
The OP said that he's swapping into an E90. I wasn't familiar with that car so I had to punch it into my DuckDuckGo search engine. It's a V8 powered BMW first introduced in 2007. Here in TX near the big cities, he'll have to pass emissions. If the car were older than 25 years, then he'd be exempt from emissions testing.
Thread Starter
Teching In
Joined: Jul 2021
Posts: 9
Likes: 2
You’re right. The E90 is the BMW 3-series one generation older than the current one. It’s natively an inline-6, but this model lends itself well to an LS fitment. I also learned that in TX emissions testing is done with an OBD2 scan (no sniffer), looking for vin, emissions equip, and controlling the check-engine light (MIL) to prove it works.
The gentleman selling the E90 kit suggested I think about parallel wiring the GM ECU with the Terminator, with the Terminator running the engine and the GM just monitoring things and driving the OBD2 port (Terminator has no ODB2 functionality). Not sure if the check-engine control would work doing this but its a start. I’m gonna need a server room in the BMW for all these computers, LOL!
I’m sufficiently ignorant to be tempted to hack the BMW CAN and see what’s going on. Its a hybrid. Most of the instrument cluster is hardwired, surprisingly, and it only drives seems to the tach guage and MIL lamp (I think) from CAN. Not sure about other switches and controls, but thats a problem for later.
This kind of thing will be a growing problem for swappers as emissions regs become universal. A programmer, an electrical engineer, and a mechanic walk into a bar….
The gentleman selling the E90 kit suggested I think about parallel wiring the GM ECU with the Terminator, with the Terminator running the engine and the GM just monitoring things and driving the OBD2 port (Terminator has no ODB2 functionality). Not sure if the check-engine control would work doing this but its a start. I’m gonna need a server room in the BMW for all these computers, LOL!
I’m sufficiently ignorant to be tempted to hack the BMW CAN and see what’s going on. Its a hybrid. Most of the instrument cluster is hardwired, surprisingly, and it only drives seems to the tach guage and MIL lamp (I think) from CAN. Not sure about other switches and controls, but thats a problem for later.
This kind of thing will be a growing problem for swappers as emissions regs become universal. A programmer, an electrical engineer, and a mechanic walk into a bar….
TECH Fanatic
Joined: Jul 2007
Posts: 1,802
Likes: 332
From: Wilmington, De
There is no reason to run without cats, and in your case, you can either just stick with the GM ECU or run the Holley as a piggyback. The benefit to the piggyback setup would be that you can handle the tuning through Holley's software instead of HP Tuners.
Trending Topics
I'm set up the same. While I don't have to run my 63 Chevy II wagon through emissions my guess is it would pass as I run cats(stainless Works) and have no CEL issues.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo I understand the reason but for the average folk that's more than double the expense just to tune. For most people one good tune and your set without worrying about 2 ecm's and extra wiring. My stock e40 ecm manages my Ls2 just fine.
Another thing to think about is in NY you are able to swap engines from one vehicle to another legally, but the catch is it has to be the same year or newer. AND, it has to be from the same style vehicle. IE, No truck motor in a car. The key to that would be ensuring that the ECU reflects the correct year. Not sure that you can change your VIN in HP Tuners, but at least in NY that doesn't matter as much as the year of the motor.
Another option is using your stock ECU and fool it to think that it's controlling the LS motor. Not sure if there is a program that you can use to flash your BMW ECU to not report the engine specific codes, but that could be a good option if possible. You basically have to add duplicate sensors to your engine. One for Terminator X or GM ECU and a second pair for the BMW ECU to be happy. I've seen where Mustang and Porsche guys do that successfully.
Another option is using your stock ECU and fool it to think that it's controlling the LS motor. Not sure if there is a program that you can use to flash your BMW ECU to not report the engine specific codes, but that could be a good option if possible. You basically have to add duplicate sensors to your engine. One for Terminator X or GM ECU and a second pair for the BMW ECU to be happy. I've seen where Mustang and Porsche guys do that successfully.
Teching In
Joined: Mar 2015
Posts: 5
Likes: 0
@ryeguy2006a - that's an interesting idea. That would be the piggyback PCM swap idea, right? I'm researching a 5.3L into an 05 Crown Vic but it has to pass emissions here in the Raleigh NC area. Plus, I've got my eye on several local BMW 3 series cars that would be great. Again, would have to pass inspection.
Seems like that would let the chassis / car PCM handle the inspection plug in - MIL and VIN check and let a standalone PCM (Holley, GM, etc.) control the motor and / or transmission. As long as you visually have cats in place and if necessary it passes the sniff test AND your inspector isn't overly savvy ("Hey, what's an LS3 doing in this 2004 BMW 330CI?!?"), it would seem like you'd be legal, smogged and ready to roll.
Seems like that would let the chassis / car PCM handle the inspection plug in - MIL and VIN check and let a standalone PCM (Holley, GM, etc.) control the motor and / or transmission. As long as you visually have cats in place and if necessary it passes the sniff test AND your inspector isn't overly savvy ("Hey, what's an LS3 doing in this 2004 BMW 330CI?!?"), it would seem like you'd be legal, smogged and ready to roll.
Teching In
Joined: Mar 2015
Posts: 5
Likes: 0
@showdog75 -Your BMW PCM runs your LSx properly? Really...I assumed you had to swap PCMs or piggyback. Is there a list of OEM PCMs that can be tuned to manage the LSx?
TECH Addict
Joined: Oct 2016
Posts: 2,513
Likes: 480
From: PDX-OR-USA
If the BMW was originally a v8, I could see getting it to run a Chevy engine, you'd have to really know the electrics..
The big issue is a 4.0 V8 is big in BMW terms and the fueling would be tricky. That ECU takes no prisoners..
The big issue is a 4.0 V8 is big in BMW terms and the fueling would be tricky. That ECU takes no prisoners..
@showdog75 -Your BMW PCM runs your LSx properly? Really...I assumed you had to swap PCMs or piggyback. Is there a list of OEM PCMs that can be tuned to manage the LSx?
Joined: Mar 2010
Posts: 436
Likes: 41
From: Vancouver area, West coast Canada
The typical "Plug in" OBD2 emissions test is looking for emissions "readiness codes" that the stock ecu generates through self diagnostics of its controlled systems. They also usually look for VIN match etc. No way to get the holley to produce either of those. And, a piggybacked stock ecu will probably not complete readiness codes since its not controlling fueling and can't check O2 sensor response.