My car threw a CEL with code 43 today.

[Bad_dude]

So i have been fighting with the 43 as well for the past couple months. I finally figured it out. (And I did try 4 different O2 sensors)

So I had the bogging as well. My MPG went down to around 20mpg and I was running very rich.

What my problem was, was the fuel pressure regulator. I ended up grabbing one at a JY just to test it and it fixed it. I tried just about everything in the manual.

You should try checking your fuel pressure on the rail with a gauge and see if it is in spec. Easy way to tell if your FPR is bad.

Is your bogging down at all speed or only right after shifting into 4th gear? I let go a bit then it pick right back up and go fast. Wouldn't fuel regulator issues occur throughout your acceleration?
The JY around my area doesn't any CB7 parts. So I have to go Ebay and they want at least $25 for it and it should be that much. Could any one find one for me and mail it? I live in Fullerton, CA
Thanks.

[wed3k]

Wow, a Code 43 that really DOES have to do with he fuel supply system? That's a first! (I don't mean that sarcastically... in about 30 instances I've seen on this forum, maybe more, it has ALWAYS been the o2 sensor.)

if the diaphragm was broken then fuel couldve been leaking into the intake manifold. the code set for 43 is probably 50 mv to above 950 mv.

so yes it can be fuel related but anything can cause an oxygen sensor to read rich or lean. it's always best to test instead of throwing parts at it.

[deevergote]

Eh, I say a 20 year old o2 sensor is worth replacing, even if it's not the cause. Since it usually IS the cause, it's often going to fix the problem. If it's not... it was time for a replacement anyway!

[wed3k]

i completely agree, id honesatly be surprised if one lasted 20 years. toyota a/f sensors usually go out around 100k. good money makers.

[Bad_dude]

i completely agree, id honesatly be surprised if one lasted 20 years. toyota a/f sensors usually go out around 100k. good money makers.

What's an a/f sensor?
I got a 99 Corolla VE with 158K miles on it.
Thanks.

[wed3k]

air fuel sensor like one that ranges from 1-5 volts and instead of fluctuating voltage, the amperage fluctuates.

toyota started bringing them in the 00's. my 02 tacoma motor is equipped with one and are pretty expensive.

[Bad_dude]

air fuel sensor like one that ranges from 1-5 volts and instead of fluctuating voltage, the amperage fluctuates.

toyota started bringing them in the 00's. my 02 tacoma motor is equipped with one and are pretty expensive.

Ooh, so I have a 99 corolla it doesn't have it then.
Thanks.

[Oreellyfool]

So how did you test your fuel regulator?
Thanks.

You connect a Fuel Pressure gauge to your rail, right side, there is a bolt (The one you releive fuel pressure from) I attached mine there.

The pressure (Off the top of my head) is suppose to be between 36-41.

If you really lost gas mileage (Generally means she is running rich), think of the things that would make it run rich.

And my bogging down was quite random (let me try to put this into words... might be tough)
It would bog down only when I would not really be pushing too much on the gas pedal. But once I pushed it past 50% or to the floor it would stop bogging. So I figured once I open up the throttle body and gave it more air, it would lean out the mixture, thats when I figured it was basically getting flooding (running extremely rich). So instead of throwing every part at it, I buckled down on testing things that could make it run rich. (ie, FPR, O2, EGR...)

[Bad_dude]

It's looks like it's the O2 sensor for me.