Hi everyone I need some help my RA accelerates to almost 3000rpm when I'm in park or neutral, and it happened today when I was in a traffic congestion, my car is automatic, last month I changed the air compressor and I think this is happening because of this, because when it is accelerated I turn off the air and the rpms goes to almost 800 which is normal, I went to the mechanic that fixed the air and he check it out and told me that it have to be something else but i'm not sure of this, my car had has the check engine light on for more than a year because the car has no catalytic converter but when this happened I scan it and it gave me 4 codes ,some of the codes : P0171: System too Lean, P0134: Heated Oxygen Sensor No Activity Detected , P0506: Idle Control System RPM Lower Than Expected , . Well thank you guys any comments or suggestions would be appreciated.

 

sounds like toyota got there hands on this one...

 

Well I don't have a cat, and I don't have a check engine light, and I know others don't have it either with no cat. Honestly , if you have 4 codes, knowing what they are would be the most helpful info so we can help you....

 

check your floor mat ahah

 

Well checking out my things found some of the codes : P0171: System too Lean, P0134: Heated Oxygen Sensor No Activity Detected , P0506: Idle Control System RPM Lower Than Expected , I miss one

 

First thing that comes to mind is a bad o2 sensor

 

agreed, but why would A/C cause it to accelerate the RPM?

i mean my A/C makes it fluctuate, but i don't remember it going that high, then again i haven't used my A/C since last summer...

And that's kinda F*ed if you've been driving lean for a year lol, i would take care of that...

 

I'm having a similar issue, when I'm stuck in traffic doing 5-10 mph and it's hot outside( in the afternoon only, in the morning no issues), my car accelerates as well up to like 1500-1700 rpm but turning the AC off doesn't lower the rpm. My car is also AT. Doing some research online I have found that the throttle cable being to tight might cause this or the IAC or the throttle body being dirty.

 

When I went to the guy that fix me the air compressor he told me exactly that, but what can I do with the throttle cable??

 

The O2 sensor that goes after the cat is broken I don't know how or when but one of the cables seems to be cut or burn something like that, can this cause a problem like this??

 

adjust the tension? adjusting the tension is easy, if it's tight, you need a little bit of slack...there's a bracket at the end of the cable, and some nuts, if you look at it, you should know what to do...it's not rocket science...if it has slack and is sticking, buy a new one

...it might cause idling problems, but i can't see it having anything to do with your air conditioner...someone who knows more about it can answer this, i just know the failure of any sensor to do with engine control is bad, and it should be fixed...

 

Well there you go. I'd try to reconnect the wiring first to see if it's that simple of a fix. (disconnect your battery 1st) if that's not an option then get a replacement, those codes all seem to be caused from a bad o2 sensor , or in your case a disconnected one.

 

^^+1 What he said.

 

Im willing to bet the wiring is rubbing against the heat shield. This happened with me (not the idle though). Then everytime it would rain while driving, the ecu fuse would pop. I didnt throw any codes though, so it took a while to find the problem. An o2 sim will fix the light for the cat. What mods do you have? The wrong size diameter intake at the maf could cause the sysrem too lean code.

 

What do you mean when you say that the wiring is rubbing against the heat shield?? If you can please PM me to know how you fixed your problem. My mods are injen CAI and OBX headers.