O2 sensor -vs- air/fuel ratio sensor
 

Sometimes brands other then Denso or Toyota cause the check light to keep coming on. If going with Denso get the one that fits the year/model/engine/etc versus a universal type.

Both sensors do the same job but have different operational designs, performance, capabilities and are not interchangeable from an operational standpoint.

The 02 sensor has a very narrow band it can operate in. If the air/fuel range is outside this band the sensor can not respond. This problem was solved by the A/F sensor having a much wider band.

The change in part started with cars built to meet California emissions standards.

Up until 2002ish the Camry was built to either California or Federal emission standards.

The Federal standard car may have used the 02 sensor, the California the A/F (assuming it was available to use at that time) as this sensor had better performance and thus capability to achieve lower emissions. It was common for the first sensor (upstream) to be an A/F sensor and the downstream to be a 02 sensor. The performance of the 02 sensor being good enough for it job in this location.

There is a sticker under the hold stating which emissions standard the car was built to.

When picking a sensor make sure it meets your cars emissions standard. This being Federal (49 states) or California emissions, upstream/downstream, etc.

Don't assume both sensor are the same or are interchangeable performance wise.

Joey,

I cant say thanks enough- that clarifies everything!!!!
It makes complete sense now, my car is the California
standard too.

I am looking to get the maximum amount of mileage that
I can get from this 2.2/auto!

The car seems to be in a good state of tune, do you think
that just getting myself a brand new Denso/Toyota (make)
A/F sensor + installing it on a car that already runs nicely
could pick up anything in the mileage dept at all??!

I got about 250 miles on a half tank +/-(18.5g tank?)
60% highway 40% city - about 27-28mpg I came in
with/estimated.

And other than an air filter, plugs, wires, pcv, etc. what
else might you suggest for any increase in the mileage dept
at all???!!

Low-restriction cat converters... air intake "kits"...... those
high-performance K+N air filters??????!!

And again, THANX!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Sincerely, Bob Z. :)

As your mileage is very good for the kind of driving you do replacing the sensor may not do much if anything.

Sensors can become sluggish in responding to A/F changes and drag the MPG down, or can fail and drag it down a lot.

Most likely you will not see any improvement with aftermarket intakes and filters. I don't recommend these.

Not sure on the cat replacement. You might check posts at the Toyotanation website on these types of things.

If you do decide to change cats keep the old original one. Don't scrap it, sell it or allow whoever installs the new cat to keep it! A scrap cat may be worth around $70, which is why the installer may want to keep it.

The reason for you to keep it is if you ever want to convert back the original cat is far superior to any aftermarket cat!! Toyota only sells the cat with the exhaust system attached thus their price on a new cat will be very, very high.

Other things that can be done are less dramatic. Too low of tire pressure, excess weight in the car, changing to synthetic engine oil, use the lower recommended engine oil viscosity, don't use the AC but don't roll down the windows.

The link below has some suggestions, some are more reasonable then others but does give you ideas.

65+ Vehicle modifications for better fuel economy - EcoModder.com

One thing you might do is install a real time MPG monitor that taps into the cars ODBII system. These devices can also monitor the A/F-02 sensors, engine lean or rich condition, etc.

Joey,

once again, I can't say thanks enough!!!!!!

I did think the mileage was fairly decent, with
all things considered too; just wanted a 2nd
opinion I guess...lol!!

And I will check with/join ToyotaNation also!!

Probably won't be changing the converter,
when I consider things now as well......
Just was a thought of a low restriction
converter helping to squeeze a few more
MPG!!!!

I appreciate the link too!!!!!!!!!!!!
:) Will definitely check it out!!!!!!

I will check out the real-time MPG
monitor thingy also- sounds interesting!

Just as long as it would be a relatively
"passive" item- as in it wouldn't be
anything that messes with ANYTHING;
relating to getting my next inspection
sticker?!!!!!!!!!!!!!!!!!

Again, can-not thank you enough for
ALL the info you provided for my
questions my friend!!!!!!!!!!!!!!!!!!!!!!!

I work with computers in all kinds of
ways, as a little side-biz for myself,
if you ever need anything at ALL-
just lemme know- as I just might have
something you may be looking for???!!

Sincerely, Bob Z. :)

For what's its worth, I replaced a A/F Sensor today on my 2000 Camry (California emmission) 2.2L, 4 cylinder engine as I was getting P1135 and P1130 codes. I bought the sensor for my toyota parts store ($200.00) and because its only a 4-cylinder the sensor sits right in the front of the engine and literally took 5 mins to switch out.

I disconnected my battery before starting the job (not sure why I did) as it took no time at all. Anyway, upon starting her up no check engine light and no code errors when I plugged in and ran diagnostic test. I'm not sure the codes cleared because I disconnected the battery or because the part did the trick (???) Time will tell I guess.

R,

Todd,

what were those codes??
(as in running lean, etc.)

Just curious......

And yes, my A/F sensor
is right in front as you said
yours is!

Thanks, Bob Z. :)

Debunker: I had a bunch of codes and what I thought to be several unrelated problems. I initially reported codes P1130 and P1135, as I thought, upon doing research, those were related and would be taken care of with a new A/F sensor. In addition to those two codes I was also displaying P0125, P0171, P0420, and P1133. Since I replaced my A.F sensor yesterday I've had no CEL and no codes. Clearly appears the toyota A.F sensor fixed all, yes all, the codes.

hope that helps!!!!

Todd,

that's cool, I didn't think just changing
one part- could clear up 6 codes?!!!!!!

Wow...... I bet you were happy, to NOT
see the light come back on. 6 codes
fixed by installing 1 200$ part- not too
shabby at all!!!!

Thanks again, Bob Z. :)

P1135
 

Hello, I apologize for getting in on your thread but I`m a newbie and i`m having great difficulty opening a new topic.

I bought a 2002 Toyota Camry LE, 4 cylinder with 124000KM on the metre last year, there was absolutely no "CEL" on it until I filled it with regular gas. I called the dealer back and was told that the previous owner had babied the car and was given premium and that may be the problem.

I ignored it up until last month, as I want to sell it and invest in a 2012 Corolla.

The mechanic checked it and told me it was P1135 .

Any idea on what it may be? What most likely is wrong with it.
There is 128,422 KM on the metre now.

I have taken the battery out over night, closed the gas cap tightly ( heck i even bought a new gas cap ), thinking of getting new spark plugs etc..

The car is in amazing shape aside from this CEL , no rust anywhere visible on the vehicle and drives like new.

Any Insights will help!
THANKS
Lilly