Okay, so I've been driving my car for about 2 weeks since I took the turbo off - I was using an FMU...

Now that I have the car running - it seems to run fine except i can tell it's running rich. Finally today I got my first check engine light, got the code and it's code 43 "Fuel Supply System".

So I did a bunch of searching on here and found a lot of people saying simply #43 = O2... well it doesn't seem that simple to me... anyway, one of hte suggestions was to go out to the car and pull off the fuel pressure regulators vaccum line... which i did, the car doesn't like it and idles rough.

So here are the symptoms - Have been driving for two weeks with no changes, until today I got code 43. When I idle her with snow behind the snow turns BLACK. I'm using tons of gas, like 10mpg.

So it seems to me, my fuel pressure is too high for some reason or another...

Everything on the car right now is stock...

any ideas?

 

I was getting code 43 after I had my car dyno tuned. I replaced the primary O2 sensor and the code never came back.

My theory on that is the sensor was already contaminated from running rich prior to tuning, then on the dyno, the first few runs were ultra rich, so it further contaminated the sensor.

The thing is, you can remedy the situation by replacing the primary o2 sensor, but the cause is from running too rich.

 

so possibly, while the turbo was on there It ran way to rich, contaminating the sensor and the sensor is now throwing code 43 and making my car run richer then it should?

why isn't it throwing an O2 code if the O2 is malfunctioning...

I guess what has me worried is what is makign it run rich in the first place... i would replace the O2 right away if i knew it was what was making it run rich...

It seems to me i've been running rich for the last two weeks, and that is finally catching up to the O2? if that's the case replacing the O2 won't fix the rich problem - which will dystroy the new O2... so i'd have to figure out the rich problem as well - how would I look for other causes of running rich?

Or - has the O2 been casuing the rich problem all along and I just need to replace that?

 

code 43 is caused by fuel trim exceeding a certain threshold... basically, the ECU thinks the car is way out of tune.

What does it use to determine this? O2 trim, as determined by readings from O2 sensor.

Before you do anything, reset the ECU and see if the problem goes away. If it doesn't, O2 sensor is the next place to try. If that doesn't do it, look for what changed to make the ECU try to make excessive fuel trims.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blundar &raquo;</TD></TR><TR><TD CLASS="quote">code 43 is caused by fuel trim exceeding a certain threshold... basically, the ECU thinks the car is way out of tune.

What does it use to determine this? O2 trim, as determined by readings from O2 sensor.

Before you do anything, reset the ECU and see if the problem goes away. If it doesn't, O2 sensor is the next place to try. If that doesn't do it, look for what changed to make the ECU try to make excessive fuel trims.</TD></TR></TABLE>

would you be willing to explain fuel trim? how does the ecu institute fuel trim?

 

bump

 

The ECU tries to steer AFR to a certain point using the O2 sensor. If it has to make excessive amounts of corrections to get there, you get a code 43.

 

Agreed.....part throttle tuning would help.

 

slap an o2 sim and the code will be gone

 

You said everything in your car is stock...does that include the fuel pump? It's real easy to overlook it.

Sonny

 

wow im having the same problem, my car is running so rich i can smell it,with the damn code 43
bump on this topic

 

don't forget that the o2 sensor itself could be causing the rich condition contributing to further contamination of itself.

All I can say is when I replaced mine, the problem never returned. I just used the secondary sensor that I had removed prior (not needed with obd 1), so it was a cheap fix

 

Same Problem Here. But I am running ultra rich, cause my Injectors are way to big. I get a code every day, but only after 5 mins of driving. Not sure if it a 43 though, most likely cause we all have the same symptoms.
Maybe you computer is still tuned to spit out fuel for the turbo.
I will try to replace the O2 sensor (it's been through alot these last 2 years), If that doesnt work I will call JET and have them Detune my fuel a little.
Thanks yall.