Edward'TLS

No. It is not that simply. If the 02 sensors are functioning, they will send out varying voltages, (like the Dow Jones index if plotted in real time), when the exhaust gas flows through them. If you add a resistor or leave the sensor in open air, the sensor voltage will always be steady, not varying. When this happens, the ECU (car computer) will think the sensors are faulty and will turn on the check engine light. In some cases, the ECU will go to the limp home mode in which the car will not go above a preset speed (maybe 30mph) to prevent engine damage.

F=ma

This method works for other OBDII Honda's... Preludes, Integra's, Civic's, just fine. Is the TL special? I do know for a fact though that it WILL go into limp mode if you just plain old install the test pipe, without doing anything to the O2 sensors.

Edward'TLS

In some cases depending on the factory ECU programming, the ECU may go to a open loop mode. In this mode, the ECU substitute the 02 sensor readings with its own default O2 mapping inside the chip. The check engine light will still turn on, and the exhaust will give out tons of pollution.
I'm not sure what mode the TL will end up in !!

Ed K

In the early days of catalytic converters there was some benefit to doing this. There were no sensors then. Now the catalytic converters are part of the engine management computer system you're only going to screw up your system, screw up your gas mileage, expose yourself to a large fine, and probably loose some performance.

The days of the seat of the pants hot rodder are long gone. Stick to the legal performance enhancement products.

jkc2121

is it possible to remove the catalytic converter, is there some way to bypass the 02 sensors? would i have to go with an aftermarket cat?

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99 MBP w/ alpine aftermarket nav/ vcr/ dreamcast (fm modulator so sound runs through speakers)/aem cai/aem pulley kit/comptech exhaust/ apexi v-afc/ eibach pro-kit

F=ma

Test pipe.

And when you do install a test pipe, you have to add a 8-10 ohm resistor to the first one, and completely remove the second one, and leave it open air.

Know that there is a 2,500$ fine for not having one, and you'll never pass emissions. If you're mandated to have emissions tests that is.

StylinTLS

Adding the test pipe is great for improving performance. But bear in mind that we're driving TLs not sportcars. I have a hi-flo cat and although I'm sure a test pipe would give more performance, all that extra work needed to bypass the O2 sensors just don't seem worth it to me. I do highly recommend a hi-flo cat. But I would't try a test pipe either.

Shoofin

Good Luck passing inspection.. I belive the OBD will detect a missing Cat and your car will not operate properly..IMO..
Ed

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Acura-TL.com - Forum Moderator

'99 TL Satin Silver/Ebony, Non/Nav, Comptech lowered, Comptech Air Filter Element, Inspire Tails, AEM Brake Pads all around, Comptech Axle Back Exhaust, "Guy Smiley" doll on the dash as my Co-driver...

Pics of my TL
Pics of my Miata! Wadya think?

F=ma

Good luck passing inspection.

Oh and I saw a an OBDII Prelude newer than my car, 2000. Put on a test pipe, cut the positive wire, spice a resistor, and walla. No check engine light first time around.

StylinTLS

Oh dayam if there's no emissions testing then screw the cat (no sexual pun). Do the test pipe..

jkc2121

so you like the hi-flo cat? is that the random tech cat? how much is it and is the performance gain noticable......and fla. doesnt do emissions testing (just changed)

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99 MBP w/ alpine aftermarket nav/ vcr/ dreamcast (fm modulator so sound runs through speakers)/aem cai/aem pulley kit/comptech exhaust/ apexi v-afc/ eibach pro-kit

RAdams

If the Check Engine Light comes on because of a problem with either/both O2 sensors, the ECU will, in fact, use a pre-determined map for fueling, etc but this "limp-home" mode doesn't limit you to any speed... it's just a "safe" set of parameters under which the car operates... at the expense of efficiency and perhaps some power.

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2000 WDP 3.2TL non-NAV
AEM CAI

jkc2121

so what is the word with the aftermarket cat? any dynos? what is the approximate power gain, cost, and difference in noise (if any)?

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99 MBP w/ alpine aftermarket nav/ vcr/ dreamcast (fm modulator so sound runs through speakers)/aem cai/aem pulley kit/comptech exhaust/ apexi v-afc/ eibach pro-kit

jkc2121

also, what exactly is "gutting" the cat? any benefits and how is it done?

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99 MBP w/ alpine aftermarket nav/ vcr/ dreamcast (fm modulator so sound runs through speakers)/aem cai/aem pulley kit/comptech exhaust/ apexi v-afc/ eibach pro-kit

DragonTL

Hey guys, I don't want to sound like a environmentalist freak, but have you guys given a thought about why the government is so strict on emissions? There is a reason for this, and the reason is that emissions have a huge affect on the earth's environment. You may think, oh what is one car going to do, but it could do great damage if everyone thought that and did remove their catalytic converters.

My suggestion is to get a high flo cat.

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2000 Satin Silver TL
* AEM SRI (blue)
* Denso Iridium Plugs
* Comptech Headers
* Comptech Springs
* Factory Bodykit
* Type S rims
* Inspire Tails
* Burlwood knob
* Tint

Jens

FYI,removal of a catalytic convertor from a vehicle will if you get caught can cost you 5000 dollars per missing convertor,this is a Federal offense not a local one.
O2 sensors as installed in OBD2 cars such as ours use the primary O2 (pre catalyst) to set and correct fuel mixture in conjunction with the rest of the sensors on the engine i.e. map sensor throttle angle etc.The secondary O2 sensor is used to establish catalyst efficiency.During specific driving cycles your car's ecu will momentarily spike the fuel mixture immediately after this the ecu will look to see if the correct voltage values are returned from the primary O2 sensor and then again from the secondary O2 sensor.Since the ecu is preprogrammed to look for specific values it will turn on the check engine light if the O2 sensors produce the wrong result on two driving cycles or twice in one trip.
Removing the O2 sensors or altering their functions will in most cases negatively affect engine performance.Removing the catalyst provides little if any improvement in performance as these modern catalysts are very efficient at what they do.If your check engine light is on the ecu is substituting a value that it is either not recieving from an engine sensor or no longer believes to be correct.The substituted value is an average based on the other sensor information.What this means is that althought the car is apparently not running any differently to the driver it is not running as well as it could.This is called limp home.
Jens

TL12

From your comment, "modern catalysts are very efficient", are you saying that an after-market high-flow cat would not noticeably improve performance?

njresendez

As I'm sure it's already been addressed installing the pre cat deletes and jpipe allows hella horsepower gains and torque as well but it is a base upgrade however,
getting the back when off is a bioo****chh

fsttyms1

We dont have precats and J pipe. This is 2nd gen.

Karanx7

iTrader: (2)

15 year rez, wow