kiker14

iTrader: (1)

I did a search, and in one of the limp mode threads, somebody said that the o2 sensor can cause it... Anyway, i pulled codes today on my 87 n/a and it gave me code 5 - no signal to ecu from O2 sensor. Before I go and get a new one, I want to confirm that a faulty O2 sensor can cause limp mode.

Also, can I clean the O2 sensor to fix it on my own?

Also, can the COLD weather affect the sensor (would a new one would work better in the 20 degree weather i'm constanly in)?

Last, if I do in fact need a new one, should i get the one that victoria british sells, or is there a better one from napa or something?

any help would be most benificial cause when i am driving along and all of a sudden my car falls into limp mode, it can be a bit scary... almost got rear ended :-/

Thanks
(sorry if these questions sound stupid, I'm still in the learning process of cars in general, esp. our 7's!)

1987RX7guy

iTrader: (3)

AFAIK S4's don't have limp home mode.

Santiago

kiker14

iTrader: (1)

ugh, well, it has all the symptoms of limp mode... like, i can't get the engine above 2000, it's like it's hitting a limiter

RETed

Having an error with the O2 sensor sensor code will not trigger limp home mode.

If the O2 sensor wire signal lead gets shorted to ground, it *can* blow circuits inside the ECU, which can cause all kinds of headaches.



-Ted

j9fd3s

iTrader: (3)

do the s4's even have a limp home?

RETed

I guess technically it doesn't.
I call "limp home" anything that prevents the car from running normally, so to me yanking the AFM is "limp home mode".

What about the TPS?


-Ted

j9fd3s

iTrader: (3)

yeah, lol works for me. how about buck home mode?

kiker14

iTrader: (1)

no, they do not have limp mode, only s5's do. The culprit in my particular problem (which is in my post "can't get engine over 2000") was a lose connection between my tps and ecu (at the tps end), so i tightened up the wires, and it's been running just fine (although i probably should get a new o2 sensor for better mpg and such)

Once again thanks everybody for your help!

are_one

Good luck changing the O2 sensor. I just bought one of those deep socket tools. Wednesday I destroyed my hands, fingers and arms in the rain as I unsuccesfully tried to remove mine, hopefully it will be much easier now w/ that tool.

theloudroom

You sure?

The O2 senor signal goes through a 10K ohm resistor before it hits any IC's in my schematics.

I'm not saying you're wrong here. If there's actually a case of this happening it might be helpful in figuring out what IC450 is.

Seems like grounding that wire might fry the sensor, but not the ECU.

http://www.mr2.com/TEXT/O2_Sensor.html