Po0420 to po1135 code

[mbillones]

Hey folks,

I have a 2001 Toyota Camry LE 4cylinder Federal Spec and about a month ago I failed my inspection test due to a "PO0420" CEL Code....so I did my research and long story short i ended up replacing front catalytic converter with a CATCO Cat Converter(CAT1061) and the rear catalytic converter with CAT Cat Converter(CAT4061)....and in addition, I also replaced both front and rear o2 Sensors with Denso brand...

Long story short, the PO0420 code now switched to PO1135 code...now I have replaced the o2 sensors twice and still that damn PO1135 code will not disappear...

ANyone here ever had this problem happened to you?

Need help!!!

[Mike Gerber]

Read this article from another forum on the P1135 code. It seems there is some confusion as to what the correct Denso part number is for the O2 sensor for your car. Compare the one you used to the one listed on this thread as the correct one for your year.

http://www.obd-codes.com/forums/view...php?f=2&t=5234

Mike

[fenixus]

Are you sure you have Federal Emission specs if you have 2 cat converters on 4 cylinder model?

My guess would be yours is California emission specs and you should use wideband Air Fuel Ratio sensor (upstream) in place of thimble type oxygen sensor, otherwise your ECU won't understand what it "says"...

check your part numbers here (look for parts marked as OE):
http://www.densoaftermarket.com/cata....php?part=o2sn

California specs uses this AFR sensor for upstream:
Denso 234-9010

Federal specs uses this o2 sensor for upstream:
Denso 234-4209

post catalytic (downstream) oxygen sensor is same between federal and california emission specs and also on V6 and i4 models, this one never changes in all gen3 and gen4 models.
Denso 234-4137

upstream one(s) differ greatly between california vs federal emission specs on gen4.

[mbillones]

well I went to a toyota parts dept here by house in nj and they confirmed that my car is federal spec and not cali spec...in addition, when i go to the denso website, the o2 sensor that they have for the non-cali model is the #234-4626...that's the first time fit direct bolt-on/replacement with no wire-cutting/splicing needed...

but now, i also heard that Toyota switched from an o2 sensor to an A/F Ratio Wideband sensor on all their cars from 2001 and on..both on cali spec and federal spec...which lead me to suspect that on all if not most o2 sensor/air-fuel ratio sensor manufacturer were not informed because none of their parts match on my car..now this is just my 2cents and no way near accurate...

for example, my car is a 2001 camry le 4 cylinder and about two weeks ago my left tail lamp wiring harness shorted out so i went to the dealer to get it replaced...i ended up spending $150.00 because I had to buy a complete taillamp assembly as Toyota, after 2001, switched companies that manufacture harnesses and taillamps...

[fenixus]

yeah, Denso aftermarket catalog lists both 234-4626 and 234-4209 as OE fit on federal 4cyl models (upstream sensor). wondering what the difference is between them...

hmmm... can you call up local dealer and ask for the part number of upstream oxygen sensor for your "federal" car?

I think as you said, Toyota changed something in 2001 model.

here, try this website:
www.toyodiy.com/parts
give it your car's VIN and look for "oxygen", one of results will be oxygen sensor, click it and it will take you to parts listing including:
a) front sensor (upstream)
b) rear sensor (downstream post-cat).

On my wife's '00 Camry Solara 2.2L the upstream AFR sensor part number is (Calif specs) 89465-06010 which is interchangeable with Denso 234-9010 or NGK 24657.

It's also hard to believe that you have actually 2 catalytic converters (upstream and downstream) on federal emission specs ... I thought only Calif emission specs have 2 cats on 4cyl model ... while federal has no upstream cat converter, also placement of AFR sensor is at top of exhaust manifold on calif model while federal one is placed at its bottom. exhaust manifold heat shields are different too.

hope it helps a tiny bit.

[mbillones]

yeah 2 sensors man...one sitting on the manifold and another at the back right after the cat....

i will go to the toyota parts dept this monday and ask them for the exact part number for this 2001 model camry and i will post it here....

[mbillones]

Cross your fingers guys as I think I finally figured this problem out....turns out that 01 Camrys uses an Air/Fuel Ratio Sensor on the front manifold and uses an o2 Sensor for the rear(after the cat)...I am 99.999% sure that this is how they do the Cali-Spec cars!!!

It's funny, my car is "Federal-Spec" but it uses "Cali-Spec" to control the emission...hahahhaa!!!

Like I said, cross your fingers folks and hope this theory works...Im just waiting for the part to come in now so i can install it....

www.buyautoparts.com