Here is a list of things i have checked so far:

spark plugs - look fine (nice brown color)
leads all test ok
no ECU codes been thrown
thermostat is performing correctly
TPS reading correctly
MAP sensor looks to be working fine

yet the rear bumper is covered in black still. This has happened only recently.

i will check the PVC valve tonight... can anyone else got any clues ?

 

umm is it like a oily black or like exhaust chalky black

 

exhaust chalky black

 

Oxygen Sensor? my black bumper went away after that..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dave0338 &raquo;</TD></TR><TR><TD CLASS="quote">Oxygen Sensor? my black bumper went away after that..</TD></TR></TABLE> x2

 

i would have thought that if the O2 sensor went bad, the ecu would throw a code ?

 

thats true. but it could be on the verge of going out. **** who knows. it fixed my prob

 

ok something to check anyway... it should output between 0v and 1v.

 

yea they can be pricey though. i had a extra one laying around

 

ok accordingy to my honda the O2 sensor is sitting at 3.28V.. which is not good... next point is... is the o2 sensor really needed seeing i have hondata setup.

Also cleaned out the PCV valve at the same time

 

if you are not going to run your o2 sensor you need to have a much better tune so that it is lean enough during daily driving.

 

update... just to make sure the O2 sensor was not the issue, i installed a new one today... however the new one was saying 3.28v as well. Which to me means the tune is running way too rich....

oh well time for a re-tune!

 

What type of fuel have you been using?

 

car was tuned for 98 octane, and it is running 98 octane so nothing changed in that department.

 

this could be due to climate change or from a rich tune. my car runs rich and its fine if i beat on her but if you baby it like i do it carbons up too a little and this happens to my car too

 

02 sensors do not read 3v.... unless it is a wideband. those read 0-5v where as a narrowband reads 0-1v. but if its reading 3.28v and its wideband, that is not rich. and also is that with the car running? or just key on engine off? with the engine on, the 02 voltage should fluctuate between rich and lean.

 

its stock the original one, and the replacement i tested is new, both read the same.

Neither are wideband.

Hondata shows 3.28V for the o2 sensor reading.

 

well if they arent reading you've got some kind of problem, maybe a open circuit somewhere or a short.