California Emissions Question - Legal to install wideband O2 sensor on stock h-pipe?

[Ghost001]

Hello,

I know that it can't affect emissions at all, but I also know that Cally is very picky about visible modifications.

Is it legal (in California) to install a wideband O2 sensor on a stock h-pipe?

I was thinking of installing it in front of the front cat, on the driver side. Or, if it's too hot there, then between the front cat and the rear cat, on the driver side.

By the way, I was also thinking of installing an EGT sensor just in front of the front cat on the driver side, to see if the exhaust gas temp is too hot for the wideband O2 sensor. Is that legal (in California)?

 

[Ghost001]

Anyone?

bdcardinal?

 

[Mike97gt]

where is bdcardinal when you need him.. he is the resident calf. emmisons nazi

 

[sgarlic]

I would think you could call up an emissions testing facility, or perhaps write to the DOT or DMV, and ask them if adding something like that is against their policy.

 

[bdcardinal]

technically no because it would be modifying the stock H pipe by possibly introducing a source of oxygen which could throw off the O2 sensors making the car run richer/leaner and causing increased emissions....

that being said, if you make it so its a PITA to see, noone will notice. also they could say that any mod which would require such a sensor wouldnt be CARB legal.

sorry about not being there right away, i had to recover from my weekend, went to the NAMM (National Association of Music Merchants) Convention. got Jasmin St Claire's autograph along with Joe Satriani and Kerry King. then i had to work today...

 

[RedDaemon]

i thought it was "illegal" to remove and replace a properly functioning sensor? or does that just apply to the cats?

 

[bdcardinal]

just to cats. technically you are modifying the section of exhaust where the cats are. to get accurate readings, it really needs to be in font of the cats.

 

[Ghost001]

Thanks bdcardinal!

I really appreciate your Cally emissions knowledge!

I guess I now have to decide how badly I want to measure the A/F.

I guess I could compromise and install the wideband O2 sensor somewhere behind the stock h-pipe, but I'm pretty sure it won't be very accurate. However, maybe it's at least as accurate as the tailpipe method they use at a dyno. I hear that a post-cat wideband usually reads too lean by about 0.5 to 0.75, but can sometimes read too rich. I also hear that a post-cat wideband is more accurate at WOT, and less accurate at part throttle.

I guess another alternative would be to get an aftermarket h-pipe, install the wideband O2 sensor in that, get the car tuned properly, and then put the stock h-pipe back on. And hope that I don't get caught while the aftermarket h-pipe is on.

Or...buy another stock h-pipe, and install the wideband on that, in a hard-to-see place. Then, for emissions inspection, re-install the unmodified stock h-pipe, just to be extra safe.

Or...and this may be the best idea...replace the stock front O2 sensor with the wideband (rather than drilling a new bung hole), and use the wideband's Nernst emulator output to feed into the PCM. This way, the stock h-pipe has not really been modified, at least not in an obvious way. Only the O2 sensor would be modified. And, it would be relatively easy to switch it back to the way it was, if necessary.

 

[GREYFOX4INCH]

some how i doubt that the average inspector would even know weather its supposed to be there or not, and for that matter, they prob wouldnt even notice it . just dont bring it to someone smart. the guy who inspected my car was trying to check the front end by jacking it up under the front of the rocker pannel.
(you dont do that with strut type suspension) most of them are dumb.