oxygen sensor help (no start) im stranded
 

long story short, the heat shield covering the lower half of the catylitic converter came loose and it wedged and got ripped off and severed the wires for the second o2 sensor. the engine stalled and i pushed the car back to my inlaws house. tonight i bought a bosch o2 sensor that was for the rx8 but was the universal sensor, meaning it had to be wired. i wired it to my original connector that had a good portion of wires hanging off of it. i wired the following colors together:

original black to bosch white
original blue to bosch black
original white wires to bosch grey wires.

this is per the chart that came with the sensor. i soldered the wires and coered them in heat shrink tubing. i installed the new sensor and the engine still will not start. when cranking i dont see much of a bounce on the tach. the car is an 05 with a 6spd. any help would be MUCH appreciated.

the sensor shouldn't be preventing the car from starting. It's just there for emissions.

i was thinking that the pcm needed a signal from the o2 sensor for some reason and that it may cut spark and prevent the engine from starting if it didn't get an adequate signal

Catastophic damage to vehicle wiring does not equal possible fuse blowage to you?

You need to check all the (3) fuses underhood, marked 'engine' and those inside the footwell particularly the 10amp 'room' fuse....

i'll head out with my multimeter. thank you. i checked them visually but felt that i should use a meter.

A short in the O2 sensor harness will blow the ENG fuse. This is your issue. No signal is needed from the sensor to start the car, but that ENG fuse is needed for quite a few other bits :)

Simplest solution is to disconnect the harness (top of the bellhousing, reach down behind the upper intake manifold, more center than the oil filter. Might be a PITA if your engine is hot or bone winter cold) and drive without it to become unstranded. As the rear O2 sensor is just emissions anyway, the performance and health of the car will not be impacted. Correct before the next emissions check, when the light gets to you, or when you can, whichever comes first.

i did not see the ENG fuse in the fuse block under the hood or the block in the driver's side footwell.

i'm working on posting a pic of the fuse block cover. i did not see an ENG fuse and i only saw one ENGINE fuse, not three. the ROOM fuse in the interior fuse block was good

my phone would not send a pic to my email account, so i used my mother in law's phone and the picture quality isn't that great, so i apologize in advance. here is a pic of my fuse cover:

Attachment 237823

https://www.rx8club.com/attachment.p...1&d=1326072382

Sorry, was remembering my Miata instead of my 8. Miata's is labeled 'ENG'. I circled it.

ok, that fuse was good. any chance the ecu is fried?

No, not from that.

It's got to be a fuse. :dunno: should have been that one.

Describe exactly what happens when you put the key in, turn to acc, and then to on, then to start.

They're marked IGN....if there is no clicks or buzzes when you turn the key it's most likely that big 30amp.

everything is normal when the key is in the accessory position. i get the usual beeping and the engine cranking is normal. the ting that i notice is that the check engine light flashes when i crank the engine and i can hear a "whirring" sound coming from the front of the car. kinda sounds like the starter winding down after cranking but is really pronounced. perhaps it is because the car has never had a no start issue and i'm not used to that sound. the battery was really drained so i removed it and hitched a ride home with my wife. i'm going to trickle charge it and as faster cranking will be much appreciated by the 8.

i'm really hoping i didn't short the signal wire and feed 12V into the ecu when it uses much less for that signal. i wouldn't mind finding a pinout of the ecu so i can start backprobing.

Record the sound of u starting the car might help.

That sound you described as "the starter winding down" is more than likely just the air pump. This is random, but check the fuel pump fuse/relay. Shorted our extra truck out while jump starting a friends car and it killed the fuel pump relay, causing a no start condition.
Can you hear the fuel pump priming when you turn the key to the "ON" position?

i'll have to take a listen for the pump, but as i recall i could not hear it.

i'll take a video of the engine cranking from inside the car with my digital camera and post it up.

i'll post the video tonight. i'm going to try and test the pcm tonight. i spoke with a tech at the dealer and he thinks the pcm may be fried..

got it fixed. must have went too quickly over the fuses and missed EGI fuse 2. don't know how i did that. i want to blame it on being in the cold and it being dark but there's no excuse. i found the blown fuse tonight and replaced it and the 8 ran perfectly. don't i feel like an amateur, lol. i appreciate all of the help in getting the 8 back on the road!!

Good news mate!

This thread just saved my ass today... 10 years later, lol