driving with cel???

ocbaud

Member

May 7, 2005

239

1

18

Midwest City, Oklahoma

Oct 14, 2005

#1

• Oct 14, 2005

• #1

ok, right now my service engine light is on because of my o/r h pipe. i have mil eliminators on the way but i'm curious about something. With the engine seeing that the cats on on there, does it actually affect performance at all?

i've heard conflicting reports on it. some people on here say that it does nothing and running with the o/r midpipe does nothing bad with the light on. others say that it causes the computer to retard timing and/or run really rich. so which is it really? and where is the evidince?

 

sgarlic

Founding Member

Apr 21, 2001

3,085

1

56

Oct 14, 2005

#2

• Oct 14, 2005

• #2

No, it doesn't affect your driving.

The rear o2 sensors do nothing but monitor the efficiency of the catalytic converters, and then send a "good" or "bad" back to the PCM in the form of an electrical signal. MIL eliminators simply send the "good" signal to the PCM all the time.

The front o2 sensors are what affect lean/rich conditions. The evidence is in any Ford manual, common knowledge of HO2S systems, etc.

 

03ghoststang

Well-Known Member

Jul 16, 2005

1,930

1

57

Los Angeles, California

Oct 14, 2005

#3

• Oct 14, 2005

• #3

it should go rich and back off timing from what i heard that is why they always recommend getting the MIL's or shutting off the rear O2's with the tuner but never actually experienced it when i installed my O/R X-pipe but then i swapped it to a catted due to how loud it was

 

ocbaud

Member

May 7, 2005

239

1

18

Midwest City, Oklahoma

Oct 14, 2005

#4

• Oct 14, 2005

• #4

see what i mean??
different reports

 

sgarlic

Founding Member

Apr 21, 2001

3,085

1

56

Oct 14, 2005

#5

• Oct 14, 2005

• #5

ocbaud said:

see what i mean??
different reports

Click to expand...

Different reports, but he's wrong, and I'm right.

Here's a good read: http://v8sho.com/SHO/TSB0197HO2SServiceTips.htm

Note the difference in names. Upstream = fuel sysetm monitor , downstream = catalyst monitor