The Lotus Cars Community banner

1 - 13 of 13 Posts

·
Registered
Joined
·
23 Posts
Discussion Starter #1
Has anyone experienced any differences in emissions between the stack V8 ECU and the High Torque Upgrade flash? Especially for California testing? How about the High Torque Upgrade vs something like PUK's version of the HTU?

I did a search but found nothing specific.
 

·
Wingless Wonder
1988 Esprit Turbo
Joined
·
5,863 Posts
The 'official' HTU should pass US emissions (which is 50 state applicable in the V8 era), after all it was a factory flash in later years. ISTR that there was different variations for various years, [email protected] will probably comment.
 
  • Like
Reactions: actwon

·
Registered
Joined
·
3,384 Posts
Carbuff is correct, the HTU is supposed to have been for all 50 States. It was officially an "upgrade" adding some more performance but it also corrected some "issues" with communication having to do with allowing the different State's computers to "talk" to the ECU during an inspection. It was originally introduced into the later production V-8's and then Lotus USA offered it to all of the previous V-8 owners. First it was only offered to those in States where they had issues passing inspection. Then it was offered generally. As far as anyone knows it doesn't change any of the emission parameters, it only deals with communication problems , actually timing compatibility across the OBD-2 port. For performance it modifies the boost limitations at lower RPM's. I consider it a useful upgrade if your car doesn't have it. If you are in NY or Cali you need it so the State can communicate with your car. The HTU is factory and still limits the performance enough so the factory could warranty the car. Any of the aftermarket offerings do not offer the same protections but do give a bit more power. If you have the HTU it should say so either in marker or a label on the case of the ECU. Only Lotus USA can do this reflash. The HTU is also supposed to reset the readiness flags quicker so you can pass inspection. I don't know if that is true, some seem to take forever to reset but in just about every State they will pass you as long as most of the flags get set. Any upgrade besides the HTU means unsoldering a chip, soldering in a socket and installing the "upgrade" chip. Not sure exactly when Lotus offered the HTU as standard in production but because the ECU could have been changed out you should check to see if you have it no matter what year your V-8 is. Because no one has seen the official code no one can say if there are any differences between any HTU. As for passing inspection, if you go with an aftermarket chip you save the OEM one to put in to pass inspection and then swap the chips after you pass. Depends on your State if you really need to do that, some States are more strict in emissions than others.
David Teitelbaum
 

·
Registered
Joined
·
23 Posts
Discussion Starter #4
Thanks for the good info!

I'm hoping I'll have my '99 in a week or so.

I'm so concerned about passing the smog check that I would install Marcus' Sport Cats and Exhaust for normal use to preserve the stock pieces, and then temporarily swap the stock pieces every two years only for the test.
 

·
Registered
Joined
·
3,384 Posts
In some States, not only do they measure the tailpipe for emissions and connect to your computer, they also do a visual check to make sure the car has the OEM emissions systems intact. For example, even if you can pass emissions, if they don't see a catalytic convertor, you fail. If they don't see the MIL light during start-up go on and then off, you fail. If your V-8 is in tune and running well, you don't have the MIL lit and you don't have any codes you should pass. The biggest reason for failure is not having enough readiness flags set. If the battery dies or is disconnected, you must reset all of the flags and that can take a while.
David Teitelbaum
 

·
Registered
Joined
·
23 Posts
Discussion Starter #6
@David:
Thanks for the info about the readiness flags, I’ll need to read up on those.

I’m very familiar with the California Smog Check 2 program, I worked on the pilot program at CARB as a student engineer. Most of the BAR guys are pretty cool about things, as many of them were car guys too. They just get upset when it’s obvious that someone is not making a sincere effort at emissions control or they’re trying to hide something. They know they can’t control anything before or after the inspection, but they take their jobs very seriously.


Were the stock cats as bad as I’ve read in a few threads? The consensus seems to be that they were very restrictive, made for a horrible sound, and disintegrated in short order. That’s what is fueling my paranoia about preserving them only for the test.
 

·
Registered
Joined
·
3,384 Posts
The OEM cats are fine as long as you don't abuse them by dumping raw fuel into them and burning them up.
David Teitelbaum
 

·
Car Adicted
Joined
·
250 Posts
The OEM cats are fine as long as you don't abuse them by dumping raw fuel into them and burning them up.
David Teitelbaum
Jay, I would say if you dont mine the work the car without cats is an absolute beast. Turbos spool up super quick and definetly is a different car.
 

·
Wingless Wonder
1988 Esprit Turbo
Joined
·
5,863 Posts
This was an emissions question (@sleekgt is knowledgeable about the ins & outs of California testing). I don't know if it has been answered.

That said, I have helped V8 owners install cat-back exhausts (just straight pipes/resonators after the OEM cats, really) and they sound err, 'healthy'. Don't know if this type of mod would fail California's inspections, after all its just the muffler, not the emissions equipment.
 

·
Registered
Joined
·
3,384 Posts
Some States, California among them, visually inspects for the presence of the cats. If they aren't there you fail automatically. The cats are part of the muffler meaning they also control some of the exhaust noise and removal will increase the noise. You could gut the cats and maybe get away with it, they would think they are there but when they test the emissions they will know the cats aren't working.. They will also see the extenders on the O2 sensors so you don't get error codes because you gutted the cats. The inspection system is set up to make sure the emissions systems on the car remain intact and working.and California is among the strictest of all of the States.
David Teitelbaum
 

·
Registered
Joined
·
253 Posts
You'll need working cats to pass CA emissions, no way around it. You're also supposed to have only CA approved cats, which may or may not be an issue depending upon the inspection station and inspector. If you fail due to a non-compliant exhaust/emissions system you can count on them checking for that on the next inspection.
 

·
Wingless Wonder
1988 Esprit Turbo
Joined
·
5,863 Posts
If the OEM, CARB-certified cats are in place but the mufflers are not OEM, is that OK in Cali?

(I expect JAE would know the answer)
 

·
Registered
Joined
·
23 Posts
Discussion Starter #13
The mufflers after the cat are not usually scrutinized, unless in removal or modification they allow a vehicle to be obnoxiously loud (we have a new law for that too).

@Esprit1: Though I would love to experience the performance, I couldn't in good conscience drive on the road without the cats. I still remember being in elementary school 3 miles away from downtown LA and not being able to see the towers. I also remember how badly my lungs burned for hours after basketball and track practice in high school. Most of us were gasping for air lying down on the benches in the locker rooms. Not so much of that now, and we have 3 times as many cars as back then. No telling how that will affect me in another 20 years, so I would be hesistant to subject today's youth to that for whatever folly I happen to enjoy.
 
1 - 13 of 13 Posts
Top