garyofelkgrove

I have a nox problem lo spd test was @1635 rpm. CO2% @15., O2%@ 0.12%, HC ppm @5ppm, CO% @0.00% And WOW the NO @664ppm FAIL and rising on tne next two tests. The truck passed at the 25mpm range. New Cat, 2 bottles of seafoam one bottle of crc smog pass new oil change,new air filter, injecters seem to be fireing. This has been a good old truck with no trouble; until now this was the the first smog failure I have had. the truck has not been abused mostly pavement use ecept boat ramps. (thats why the auto.) It is a 5vz-fe v-6 w/auto., 1998 LTD X cab, all the jokes, 175,000mi, it is a org. californian. Funny thing I can't seem to find the darned egr I think it got lost. Anyone have an ideas for me thanks:=)
this is a first time post
garyofelkgrove

Elton

i thought they dont have egr ? might be time for a new o2 sensor

garyofelkgrove

realy hmmm maybe I thought I was going blind thx

BigBallsMcFalls

you don't have an egr


high nox can be due to running lean, due to a bad a/f sensor
(I think 98 cali are a/f and not o2 for b1s1 position)

I'd start with cleaning the MAF and changing the bank 1 sensor 1 with OEM, (if it has never been replaced before)
have dealer look up your part based on VIN number to get the exact one. gonna cost you >200 bucks


you -do- need to resolve the root cause for high NOx...because if it really is running lean, you will
end up with other engine problems from the excessively high combustion temps

garyofelkgrove

thanks looks like this is going to hurt $$$$$$$ :=( the price for living in the peoples republic of add text here

TheDurk

Cali.'s and A/F's sensors started in '99. Your '98 should have one cat, O2 sensors before and after, and no EGR regardless of state. I'd start with a real throttle-body and MAF cleaning (them bottles only do so much) and then a new O2 sensor (assuming you have no CEL light on). Disregard earlier post, find your Denso part number at http://www.urdusa.com/More-Products-...6rl0qbf7o0hov7 and then buy it on Amazon for $100.Same as dealer without red box and extra $100 cost.

garyofelkgrove

This is getting interesting. Here are a few more facts that may shed further light...... My Taco has one cat, no codes out, and the cel has never come on; it also still has great tow power and right there accelleration. The mpg is a little low about 16.5mpg used to get about 20 to 21mpg, no smoke tail pipe is clean no soot or carbon, has the tpical 3.4 snarl to the motor no mis or stumble all the way out. thanks for the parts web site and all you guys input.