[bigtrouble77]

I know almost nothing about cars, but removing a muffler looks pretty easy to me especially if the trade off is +15mpg and a little more noise. I'm sure I can get my mechanic to take it off and just extend the tailpipe but will it hurt the engine and will it hurt emissions? Will it fail inspection?
Thanks,
-BT


http://www.cardomain.com/memberpage/350420/2

 

[bigtrouble77]

Of course I finally found the thread about the mod after posting this but I am still wondering if anyone tried it and if it does affect the emissions.

 

[cakley]

Another guy in texas (memory) removed the muffler completly and the NOx convertor.

The tailpipe is 35mm if I recall- not that easy to find 35mm exhaust pipe.

I've put over 10,000 miles since the muffler bypass. with no "known" problems. Once again I can't see how improving the FLOW of exhaust at the very end of the car will hurt the engine. The exhaust allready has to make it though the engine block, a cat, and a NOx cat, resonator, then about8ft of little pipe before it reaches the muffler.

I've not had an emission test done. Not required.. I think I could het it done tuesday afternoon for about 20.00.

 

[cakley]

Plus your not goining to get the 15+mpg above 70 + 85mpg. What I've noticed is that I can drive the car faster without needed much or any IMA power.

Normally on my commute at 80+mph - 63miles into atlanta from 75 south - up and down some big hills I have never used more than 2-4 bars of the battery.

You've looked at my web site so te best MPG I have is 80mpg on a 400 mile trip. Thas below what others who have no muffler mod. So the mod helps none to very little if keeping a constant speed. Looks like it only helps for accelerating.

Noise- unless you knew about the mod on my car you wouldn't notice. Though I still do have a muffler and it probably kills some sound.

 

[Sparky5501]

will it hurt emissions? Will it fail inspection?

No, and No. The muffler does exactly what it's name implies, it muffles sound. This is it's primary purpose.

The emissions are controlled by your catalitic converter.

You souldn't have any problems changing your muffler to a better flowing version or removing it completely. The sound level will change. I really want to get rid of my muffler but I also don't want to loose my peace and quite.

I've been looking into the AeroTurbine muffler as a possiblility.

Cakely have you run you insight without the muffler?

 

[bigtrouble77]

Thanks for the input guys. cakley, I have a CVT so I only get 53mpg lifetime mileage so far. Do you think this would benefit CVT owners better? I've had to drive at or below 70mph to sustain my 53mpg unless it's a really hot day.

If I could get my yearly average up to 60mpg i'd be very happy. Noise isn't much of an issue for me unless it's really bad.

 

[cakley]

I didn't start my car without the muffler. I should have was in a hurry and I just swapped them out.

I wouldn't think it would be loud. It will have sound but should be far from loud. The sounds has to make it through two cats and a resonator. I've seen lots of cars with much bigger engines and only one cat without a muffler. They sounded quite.

Its a different ball game when the cats are gone.

Aftermarket mufflers weigh to much.

BigTrouble I'd recommend removing the muffler- but I won't guess at MPG improvements.

 

[Foxpaw]

Removed the NOx converter? Wouldn't that cause havok with the lean burn? Or would that somehow allow more lean burn because the LAF sensor would never register full?

 

[cakley]

The 2000 year models don't have an O2 sensor on the NOx convertor.

 

[Foxpaw]

Are you sure? Mine appears to have one - I had to have it replaced. (And they gave me the old one, so I'm fairly certain they weren't just BSing me.)

 

[Mitch]

NOx

There is no sensor whatsoever on the NOx converter of '00 models. The same applies to '01 models, so I'm told.

Mine is removed from the car for thousands of miles already. The car runs great, lean-burn is unchanged, and mpg has been going up.

 

[cakley]

Are you sure? Mine appears to have one - I had to have it replaced. (And they gave me the old one, so I'm fairly certain they weren't just BSing me.)

Probably the O2 sensor on the main cat. :idea:

 

[Foxpaw]

Without the sensor, how does the ECU know when to end the lean burn mode? Or does it just estimate based on speed, etc. on those model years?

 

[coolcat]

As far as we can tell the ECU has an algorithm programmed into it to determine when to take a break from lean burn. I wish it did base it on some external reading, becuase then it would be easier to hack it into staying in lean burn longer. While I'd happily hack into a sensor lead and apply a 'fake' voltage I really don't want to try to hack the ECU.

Now that my Inisght is out of warranty I'm going to start playing around with it. Exhaust and intake mods are up first because they'll be the cheapest. I also want to get some new wheels and tires, some laughing gas and do some more work on my stereo. I've got this crazy idea for an electric supercharger, but that one's way on the back burner.

 

[flunkysama]

Re: NOx

There is no sensor whatsoever on the NOx converter of '00 models. The same applies to '01 models, so I'm told.

I realize we are drifting off-topic, but I'll throw this in here.

According to the 00-02 electrical troubleshooting manual, there are 3 different O2 sensor configurations used. 2000 and early production 2001 models have LAF/wideband primary and a 4 wire secondary. Late Production 2001 models have a 4 wire primary and a 4 wire secondary. 2002 models have a 4 wire primary, a 4 wire secondary and 4 wire post-NOX convertor third sensor.

(If anyone knows if they changed again for 03 or 04, please post.)

So 00-02 have open loop NOX purges and late 01 and on have open loop lean burn.

 

[Rick]

Sounds right to me. I am pretty sure the post nox converter sensor is a california emissions requirement in 02 because a friend with a 02 S2000 has one post cat while the 01's don't. When Willie and I met we were doing some comparison. His 01 had just the 8 wire primary and 4 wire secondary. Mine 4 wire primary, 4 wire secondary and 4 wire post nox.

Something tells me removing the nox converter on mine would make the car freak out.