Rspct2All

Actron CP9125
I was desperate, and bought it for $70, but I saw that online it's for $40, oh well, always better than paying a shop $100+...

ANYWAYS... I found out the Check Engine Light was throwing a P0171 and a P0420.

P0171
Good info here... Regarding O2 sensor or MAF dirty/faulty...
http://www.obd-codes.com/trouble_cod...gen-sensor.php

P0420
Good info here... Regarding O2 sensor after the catalytic converter not working efficiently
http://www.obd-codes.com/trouble_cod...old-bank-1.php

I used the Actron and erased the error (cleared).
Surprisingly, after I cleared the code, the 4Runner ran smoother and responded better than before the clearing. The Check Engine Light hasn't come on yet, but usually it's after a while you drive it, it will come on if it's a maturing problem I guess...
I'll be buying the CRC Electronic Contact Cleaner tomorrow.

Thanks mkgarrison5 for the help and info you've been offering.

Any info would be nice about this post.
This is just a summary of my knowledge of this particular situation.

Have a nice weekend!

Rspct2All

The OBDII sensor was bought at AutoZone BTW... Actually, since they have the MAF sensor cleaner, should I buy that or simple CRC Electronic Contact Cleaner?

toytech76

Clean or replace the maf and that takes care of p0171. Be carefule with p0420. It usually means your cat is bad but we have had a few instances where the o2 sensor after the cat was giving false reading making it look like the cat was bad. Technically the sensor was working so it didn't have a code. More than likely it is your cat tho

toytech76

You can use simple brake kleen. Don't use anything that could possibly have any type of lubricant in it. Use brakekleen since it dries fast and leaves no residue then blow the maf out with air. No worries the air wont hurt it. Just don't touch the hotwire with fingers or anything like that

Rspct2All

Thanks toytech76, I'll keep that info/tip in mind... Which is usually cheaper? The O2 sensor after the cat or the catalytic converter?

toytech76

The sensor after the cat for sure is cheaper...BUT that won't for sure be the fix. The cat from toyota is gonna be over $300 easy. I don't know of anywhere but the dealer who sells obd2 compliant cats. I say wait till you need to get the thing smogged if you do that where you live then fix the cat problem

Rspct2All

Hmm... dang. Oh well, I'll take your word for it. They say that you won't notice any drivability issues, so I'll take your tip and focus on the MAF sensor. I think I remember seeing the sensor a bit dusty... I hope it wasn't my 4runner that I was thinking of... THANKS toytech76, again...

I really appreciate the people here in YotaTech that help so much with other peoples Toyota problems!

toytech76

Just glad to help out and share some of the knowledge that I use on a daily basis to help others out!

cgeorge

The OEM CATs are super expensive ($700+ depending on where you get it). The P0420 code is a real pain. I've had it for a while now. I reset the CEL and it comes back sometimes in a few days or - the longest - a week. Truck drives fine...

I haven't replaced any of my sensors yet. They are about $100 each.

Elvota

I just swapped a 3.4 into mine... same code from the cat. I have a hi-flow cat, so I am sure the computer is seeing this as a faulty cat.

My plan is to do this:
http://www.vfaq.com/mods/O2bypass.html

And if I can't figure that out, I may buy this:
http://www.urdusa.com/product_info.p..._id=1230100014

If you know your engine is running well, I think bypassing the rear sensor makes sense. If your cat is truly bad (clogged), you could get any aftermarket cat and just bypass the sensor. Save some money and shouldn't effect performance.

warriors_03

FYI, I had the p0420 code last week, and stealership tells me that it is the cat...so that sucks...from the dealer it is 921.23 (or something close), but after contacting multiple dealers, many will sell it too you cheaper. Below are a couple that are up to 28% cheaper...

Carson Toyota in CA:
http://www.trademotion.com/partlocat...&siteid=214915
Part number: PN 17410-62130 for the V6 with cali emissions
it was 684.08

they were lower for all parts that I was looking for...

Next was toyotapartsales.com and then champion toyota in texas (parts@toyotaworld.com) I hope that this helps a little...

Mark

MTL_4runner

X2

Electrical contact cleaner doesn't work for squat when cleaning the MAF.

MTL_4runner

Completely agree. Take toytech's advice and replace the front and rear O2 sensors (I have seen both the front and rear give false readings in some cases and both can result in a P0420 but each for different reasons). Do that first before you start looking at replacing the cats because they are big bucks (esp if you have a cali spec vehicle which has the dual cats).

Golden rule: always replace the cheap/easy stuff first.

ninjarunner

i don't mean to thread steal but since we are talking about O2 sensors, where is the best place and best brand for a wideband O2?

mt_goat

http://www.urdusa.com/product_info.p...s_id=430006000

ninjarunner

I looked at those but I thought the factory ones were narrow band? and the OBDI are wideband??

mt_goat

URD sells about 20 different O2 sensors, front, rear, narrow and wide. They should be OEM since they're made be Denso. I don't know about the 4runners but the wideband front sensors started in 2001 for the Tacos. Anything after 97 will be OBDII.

ninjarunner

so did I have it backwards, and OBDII the front sensor is a wideband? also if that is the case could I just piggyback my front O2 for my tuning needs?

mt_goat

I think I misunderstood your original question, sounds like you're looking for a wideband A/F ratio gauge. I've never heard of anyone piggy backing the front O2 sensor for that (even the newer wideband O2 sensors). I have a separate sensor for that, the older version of this: http://www.urdusa.com/product_info.p...s_id=540003768