89silverpu

I took my truck in to get smogged about a month ago and it didn't pass. The CEL wasn't lit up so I didn't even think to read the codes but about 5 months ago it did light up and I got a bad O2 code so I replaced the after cat O2 sensor and was going to eventually change the pre cat sensor but didn't have the $200 to do so at the time. The CEL went away and I forgot about the pre cat O2 sensor and didn't think of replacing it before I got it smogged. So when it failed I had to have a cerified smog center fix my truck (I couldn't try and fix it myself) and it turns out it was that pre cat O2 sensor making my truck run super rich and not passing smog, not to mention that was the reason for my poor gas mileage. So the moral of the story is REPLACE YOUR O2 SENSORS IF YOU HAVN'T REPLACED THEM AND HAVE A TON OF MILES ON YOUR TRUCK cause the truck will run a whole lot better, you'll get better gas mileage, and you'll pass smog

Jay351

Mine is overdue, got smog on feb 15th Im not worried, I got 3 months to re-test and I can do the work myself

WTAllstar

Any advice on which O2 sensors to get, I've looked at prices and they range from like $50 all the way up to $200... do you really get what you pay for?

Green93

Hey Jay you didnt pass aircare?

For those of you looking at getting a new O2 sensor check out sparkplugs.com. I was quoted $250 at the dealer and I got the exact one for $95.00.

Jason

89silverpu

Yeah thats what I get for living in California though lol

The pre cat O2 sensors are the super expensive ones, around 180 to 200 and the post cat O2 sensors are the cheaper ones around 80 to 90 from what I've seen. I went with a Bosch but thats only cause thats what my local Kragen had in stock but you might as well step up and get a decent one cause they last a long time: I just replaced mine and they had 163000 miles on them

Jay351

Hehe, I go in on Febuary 15th for my test. Truck has never failed, but the NO2 is getting pretty high! Keep my fingers crossed


Well all have pre-cat o2 sensors The post cat is only for the cali trucks. I got my NTK (ngk) oem replacment from sparkplugs.com for 37 bucks!! All the auto parts stores wanted 225+

I hope your truck is okay with the bosch crap

89silverpu

Well the Bosh crap was $80 from Kragen so I'm not too worried and I never knew that the post cat was only for Cali, What would happen if you moved to Cali and had a pickup from say, canada lol I'm assuming you don't have the one after the cat right?

Jay351

Nope, just a pre-cat o2 sensor... thats seriously messed up

the post cat is just to make sure the pre-cat is working correctly

Elton

ahh im glad we dont get smoged here

thook

Sooner or later we'll all get smogged....if you catch my drift.

(It's a joke....a pun, eh. We don't have smog reg's here, either)

SurlyJohn

Some of Oregon gets smogged, if you have more than 100,000 people in your town then you get the wonderful $21 DEQ test and charge. Basically Portland Metro and Medford are the only unlucky areas that I know of. Everywhere else is free of this BS test.
You can register your vehicle for $54 for two years, but you have to add that DEQ test to get it up to $75.....selective state smog test.....what a joke.

notanymore

people here usually recommend ngk or denso. bosch parts have given people issues on their toyotas.

MRecio

Yea NGK or Desnso's work great i put them on my rig... cheap too they or OEM identical without the price...check out sparkplugs.com

part numbers for the densos are

234-4052 and 234-4161

they run under a 100 bucks a piece shipped.

and just to be clear the pre cat sensor is the only one that really matters the second one is just a sensor to tell u when the cat goes dead and makes no difference on performance or smog.... i recommend replacing only the pre cat one unless the CEL tells you its the post cat sensor thats bad... in that case check the CAT.

89silverpu

The post cat sensors are to make sure your cat is working properly, if it senses oxygen coming through then that means your cat is not bonding whatever it bonds with oxygen properly and it lights up a CEL reading of improper catalyst or something like that, I just learned this this morning talking to my auto shop teacher and he said that the post cat O2 sensor doesn't affect how the truck runs...that would have been useful to know before I replaced the post cat O2 sensor (I would have known to replace the pre cat sensor)...if you get a bad O2 sensor reading then that means it is the pre cat sensor because if the post cat sensor goes bad then it will light up a CEL code for the cat not an O2 sensor code.

Jay351

There you go, I tend not to learn things that don't apply to my truck

Redeyejedi

i just replaced my a few months ago.
94 3vze 5sp 4x4

http://www.partsamerica.com/ProductL...pe=291&PTSet=A