aquasport17

Ok, I was able to see from the state inspection in 2005 that the code was a P0420. That mean anything to anyone?

MTL_4runner

Ok that's not a good one.
Just do a search and you'll find lots of info on that code.

bwhyit

P0420 is for catalyst efficiency. Most likely culprit is a bad Cat.

aquasport17

Okay - can i start by testing or replacing the sensors? Do you recommend any CATs that would perform stock as far as the computer is concerned?

MTL_4runner

Yep, not a cheap fix on 4runners with dual cats.
There are some ways around it though.

Ok on your 2000 4runner is it a cali spec truck? in other words, does it have dual cats?

aquasport17

00 year. I did see there is a device to get around the issues. I'd rather do it right and replace whats wrong. It's possible that with the engine running lean for many years, I burned out the CAT. Can I test the sensor to make sure? the stock sensor is about 130 bucks from toyota - but I get the feeling the sensor is probably not the culprit.

aquasport17

I found this in one of the foums .....

measure the voltage at the oxygen sensor on Bank 1 (the rear sensor, or the sensor after the converter). The voltage should be low and steady (~200mV, depends on the vehicle). If the voltage varies (e.g. 100mV to 600mV) then it's time to replace the catalytic converter. In fact, it would be a good idea to test each oxygen O2 sensor while you're at it.

MTL_4runner

The issue for you is that most of the O2 (A/F) sensor and cat testing is going to require a graphing OBD reader (either laptop PC or Palm based). If you have a Palm PDA or laptop PC then you might consider getting an Auterra or BR-3 reader to help you with this issue. Otherwise, you'll potentially be doing alot of expensive parts replacement for no good reason (it could be the front A/F sensor, rear O2 sensor or the cats that are actually causing the code.....also potentially an exhaust leak). You could also bring it into the dealer and have them verify the cat or sensor(s) as being bad, but those trips are never cheap.


Ironically the Auterra review here tackles the exact same code (but don't assume your truck will have the same fix):
http://www.troublecodes.net/articles...r_Review.shtml

aquasport17

I'm going to buy that today. Not messing around. I have a VAG COM for my VW diesels and it has paid for itself.

I have an IBM laptop with USB (no serial). What components would you recommend? I'm looking at the website for the tool now. Do I need the CAN version or just the one for 189?

MTL_4runner

No, you don't need CAN. Toyota didn't put CAN in 4runners until 2005. Also check eBay because the company sells on there too (usually a bit cheaper). That's where I picked up my Auterra back in 2001. If you have a laptop then you might also look at the BR-3 as well because it's even cheaper and does almost the same thing (Auterra has a few more features, but both have code reading and full graphing capability). I personally like the Auterra setup better and use mine alot so I'd probably opt to pay a bit extra, but that's just IMHO.

Here's the website for the BR-3 reader:
http://obddiagnostics.com/

Here's someone selling the entire Auterra CAN setup with PDA! (A-300 supports all OBD protocols and it's very portable)
http://cgi.ebay.com/ebaymotors/A-300...spagenameZWDVW

.......ok, if I could get it for $250, that one on eBay is very tempting for me too.

aquasport17

Well, I don't have a serial port. I do have a USB to Serial adapter which may work, or I'll have to buy the CAN USB one. DOes the BR-3 use USB? Can you provide a link- I didn't see much when I googled it.

aquasport17

Never Mind. I found it - No USB on that either. Does say it will work with the adapter though.

MTL_4runner

Those USB to serial adapters always make me nervous (esp if your running Win XP). I've tried a few myself and didn't find one that worked well (not that there aren't any out there that might work). Most of them seemed to be compatable with everything up to Win Millenium or Win 2000 and then support was non-existent after that.

aquasport17

Yeah - I'm going to get the USB one with CAN. Ebay for 199. Then Ii will have native USB.

MTL_4runner

That is the smart thing to do.

aquasport17

It's on it's way

aquasport17

Thanks for all your help. I may need some help diagnosing the issue further - I will read the thread you posted on it above. What type of reading should i expect from a working 02 sensor?

MTL_4runner

There was a thread a short while back where I helped someone else that was diagnosing an issue with the Auterra on a laptop (there were screenshots and everything!), but I can't find it since the serach function on YT is pretty much toast now for stuff like that. If I get more time, I'll see if I can dig it up for you.


.....finally found it:
https://www.yotatech.com/forums/f2/rough-idle-vibration-108063/

aquasport17

Thanks- I'll post the details when I get the device. I'm still not sure what is normal voltage readings for the sensors and what is abnormal. But I'll figure that out when i get the unit.

J

aquasport17

I played with the tool a bit - it doesn't look like I can get the 02 sensor test to work like you posted in your link above. Does my 4runner support that? I took some screen shots and I will post them here.