Punching Out My Cat

[Kafike]

I had to do this with my 2000 Frontier, I then had a low catalyst efficiency code spring up. Solved that by buying a set of spark plug anti foulers from napa for $6. These anti fouler plugs then are drilled to receive the downstream sensor, effectively removing it from the exhaust stream enough to trick the sensor into thinking the catalytic converter is working fine. Sorry for the brief explanation here as I'm currently surfing the net at work lol but it is explained online in several other spots if you search for it. This won't help if you live in a state where the "sniffers" are used in the tailpipe for the emissions inspection either. Helped out immensely here in NY though.

That's the trick used on the B15 Sentras to remove the CEL when you swap the exhaust manifold for a header. The stock manifold has a pre cat that fails and the motor sucks the ceramic back into the motor.

[Precise1]

I had to do this with my 2000 Frontier, I then had a low catalyst efficiency code spring up. Solved that by buying a set of spark plug anti foulers from napa for $6. These anti fouler plugs then are drilled to receive the downstream sensor, effectively removing it from the exhaust stream enough to trick the sensor into thinking the catalytic converter is working fine. Sorry for the brief explanation here as I'm currently surfing the net at work lol but it is explained online in several other spots if you search for it. This won't help if you live in a state where the "sniffers" are used in the tailpipe for the emissions inspection either. Helped out immensely here in NY though.

So the cheapest trick is the right fix?

 

B

[djratlif]

I am not saying emissions will be better, in fact they will be worse if I'm not mistaken. It will however trick the computer into working the way that you want performance and power wise. The downstream O2 sensor has to read less than the upstream sensor or it will trigger a CEL for ineffecient catalyst as Kafike stated about the sentras. So by pulling the downstream sensor out of the main stream of the exhaust it effectively reduces the amount of oxygen going past the sensor as it would if a catalytic converter was there. This is just a trick to get around the emission test here in NY where the CEL is the only thing that is used for emission inspection. However, as I mentioned before, if you are in a state with the "sniffer" devices that are placed in the tailpipe during inspection this will not help. It doesn't work like a catalytic converter does to reduce emissions, it hides that there is a problem with the emissions. Hope this helps a little, D

[ahardb0dy]

NY used to test emissions for the inspections, did they change it?

 

My old 87 hardbody even with all emission parts intact and tuned up properly used to fail the inspection test every time, thought I read years ago that Nissan rushed the VG30 into production in the trucks and that's why it had a hard time passing???

Edited December 12, 2013 by ahardb0dy

[djratlif]

 

 

NY used to test emissions for the inspections, did they change it?

 

NY has an emissions inspection still, but the only thing they inspect is whether the on-board monitors have all reset, ie. o2 sensor, evap system, egr function, catalyst function, and that there are not any DTCs stored in the ecu. This is all done by plugging the vehicle into an inspection station. There is no actual meter that reads the emission output at the tailpipe like in other stricter states. Also, this emission inspection only applies to vehicles 1996 model year and newer as the computers at inspection stations only read OBDII systems. My Pathfinder had a new inspection sticker without any problems. All thanks to a friend that overlooked the blown shocks, almost blown out ball joints, tore up brake rotors and pads up front, missing catalytic converter/exhaust pipes, dripping power steering lines and numerous other oil/trans fluid leaks. Man, I think I still owe him a few beers for that one...

Edited December 12, 2013 by djratlif

[MY1PATH]

 

why not swap your hood with a MPFI pathie so the vacuum diagram matches what you have? How would they know at that point?

I can, and I have a 93 hood to borrow. I'll just look like a goon with a different color hood lol.

[vagabond]

I can, and I have a 93 hood to borrow. I'll just look like a goon with a different color hood lol.

 

Hood doesn't look bad in a flat back

[Bubbley11]

Ever heard of "Guaranteed to Pass" I used it an guess what it passed.

[Towncivilian]

CRC's Guaranteed to Pass contains PEA, also found in cheaper products such as Chevron Techron, Gumout Regane, and Redline SI-1. I doubt it has anything special other than kerosene or some other solvents to act as a carrier. Go with the cheaper products, they will work just as effectively.

 

I wish Florida had safety and emissions inspections. It would get so many unsafe vehicles off the road. The cost is minuscule compared to the amount of injuries and deaths prevented from unsafe vehicles on the road.

Edited December 13, 2013 by Towncivilian

[ahardb0dy]

 

NY has an emissions inspection still, but the only thing they inspect is whether the on-board monitors have all reset, ie. o2 sensor, evap system, egr function, catalyst function, and that there are not any DTCs stored in the ecu. This is all done by plugging the vehicle into an inspection station. There is no actual meter that reads the emission output at the tailpipe like in other stricter states. Also, this emission inspection only applies to vehicles 1996 model year and newer as the computers at inspection stations only read OBDII systems. My Pathfinder had a new inspection sticker without any problems. All thanks to a friend that overlooked the blown shocks, almost blown out ball joints, tore up brake rotors and pads up front, missing catalytic converter/exhaust pipes, dripping power steering lines and numerous other oil/trans fluid leaks. Man, I think I still owe him a few beers for that one...

 

When did they start doing this? I haven't lived up there since 97 but back than they had the tests where the machine measured the emissions from the exhaust.

[MY1PATH]

Ever heard of "Guaranteed to Pass" I used it an guess what it passed.

 

I got a bottle of that stuff but I think its Not gonna help me here, that product is designed to CLEAN ENGINES of blockages and buildup that happens over time, If you read the instructions, its completely used up and you have a new tank of gas by the time you are ready to test. I have a Brand New Engine (I pulled it out of a factory crate myself) with 7k Miles on it, New Fuel system with 2k miles on it, EGR system only hooked up for the last 2k miles(yes this smog component contributes to build up which can cause failure later on...)

 

CRC's Guaranteed to Pass contains PEA, also found in cheaper products such as Chevron Techron, Gumout Regane, and Redline SI-1. I doubt it has anything special other than kerosene or some other solvents to act as a carrier. Go with the cheaper products, they will work just as effectively.

 

I use Chevron with Techron on a regular basis so that helps keep things clean.

Edited December 18, 2013 by MY1PATH

[Kingman]

[Precise1]

 

EGR system only hooked up for the last 2k miles(yes this smog component contributes to build up which can cause failure later on...)

In 28 years of smogging cars, the only one that ever failed due to EGR system was a 1978 VW Beetle, and that had 2 pipes with a filter in between and was likely the original. EGRs aren't usually a problem from my experience, and if they become one it is usually due to something else.

 

B

[Alkorahil]

I have seen maybe two or so fail with super-high NOX emissions from a clogged EGR.

[MY1PATH]

I have seen 3 where the EGR passages where so full of soot they appeared to completely block the flow of EG.
Other than those 3 I have not looked closely at very many.

[adamzan]

My old one always had a hard time passing. The last time the shop suggested the EGR, but I was able to squeak through by 1 point on the re test.

[Precise1]

 

I have seen 3 where the EGR passages where so full of soot they appeared to completely block the flow of EG.

Other than those 3 I have not looked closely at very many.

 

EGR system only hooked up for the last 2k miles(yes this smog component contributes to build up which can cause failure later on...)

 

My point is that the EGR does help with tail pipe emissions, and isn't an onerous or problematic (or significantly power robbing) component. While it can clog, it is simple to address (clean it) and being an exhaust gas conduit, if it is clogging that means you have a poorly running engine to begin with (exhaust gasses loaded with crap).

Doesn't make sense to say it will cause poor emissions when it only helps, but can occasionally malfunction if the engine runs poorly to begin with.

Some smog control devices are effective and makes sense, regardless of the general hatred.

 

B

[Kingman]

Many vehicles have problematic EGR valves, even when they were running perfectly fine.

 

I haven't seen inside a single TBI on a Pathfinder yet where the EGR port in the manifold wasn't clogged or close to it.

[Precise1]

Not that I have owned, but I haven't owned all vehicles.

 

Fair enough, but it is common knowledge that the TBI set up is not exactly stellar either. I wouldn't want to own one for several reasons, needing to pass smog is one of them.

We are talking about his MPFI swap, right?

 

B