1995 fails AZ emissions NOX

[whitehorsetwo]

hello ALL: I'm no Mechanic but here goes...1st time emission fail was the gas cap - new O'Reilly cap put on tight - back to the station and 2nd fail - this time NOX 3.30 needing to be 3.00 - sidenote: after a tune-up in the midwest my carburetor bogging at idle w/ air-conditioner so my brother messed with it to run smooth - have been reading about EGR's and cat converters etc but it's a tad Greek to me. Getting ready to call a dependable mechanic for help and tell him the same - he'll have to fill out the form and everything! I love my dirty white 4 Runner and hope next year to drive it the length of Baja. Thanks in advance...

 

[giro]

The catalytic converter is the magical device just before the muffler in the exhaust system. Using little pellets of stuff (my understanding is the OEM one uses a platinum catalyst), it turns bad stuff (CO (aka carbon monoxide, that "silent killer") and NO, from the non-perfect combustion in the engine) into stuff that's not as bad (CO2, aka carbon dioxide, some of the stuff you breathe out).

Basically when hot, the catalyst helps make the reaction happen. Always make sure that your vehicle is fully warmed up before a smog check, since the cat needs to be hot to be working properly.

Someone else might have the magic bullet for high NOX levels, but replacing the catalytic converter is a good general step to failing emissions. Over time the catalyst gets coated with junk, especially if your engine has problems. An aftermarket cat can be had for under $100, though the OEM ones are something like $900 from Toyota. I don't know if they use the same catalyst or the same amounts of catalyst. I do know that someone apparently found it profitable enough to steal my OEM bolt-on catalytic converter off of my '92. It was just a matter of undoing 4 nuts and walking away, and I even found all of the mounting brackets in nearby bushes.

Good luck

 

[whitehorsetwo]

thx giro: had mine stolen a few years ago in southern california - yip 4 bolts - this one's welded on! so it's a few years old but is my big worry of course - the money! appreciate yr time and giving me some knowledge.

 

[TakeitApart]

High NOx is usually from a hot motor. Timing, lean fuel mixture, carbon build up, or a bad EGR system are possible causes. Also, as someone already stated, a bad TWC (three way catalytic converter). Good luck!

 

[whitehorsetwo]

appreciate it TakeItApart! I'll have my list when I go to the good mechanic Friday. I'll let you all know. Cheers.

 

[whitehorsetwo]

Hey fellows: took my 4Runner to a mechanic who used a hose to bypass the EGR valve. I was worried it was illegal as he told me to switch it back but not right in front of the emission workers but he stamped my paper so I went throught the line for the third time and passed! Such is life and being legal. Thx Giro and TakeItApart, I truly appreciate yr time and direction. signed Randell

 

[CodeButcher]

My 86 Beater recently failed SMOG with a high NOX. A mechanic friend said if my other readings (O2, CO2, etc) were low then it is the EGR Valve. So I checked around my regular parts stores, and got quotes. The highest was $240 and the lowest $130, and all out of stock. So I went online to Rock Auto, being a bit skeptical, I found one. CARB certified, for $122 shipped. When I got it two days later, I was surprised to see it was an OEM Denso, with a Toyota parts number sticker. It was distributed under Intermotor.

I'm one satisfied customer of Rock Auto.