Ad Radar
Item Posts    Sort Order

No O2 sensor

 
mtgtool
I love my Chevy Chevette!
Posts: 3
Joined: 07/13
Posted: 07/10/13 06:13 PM

Hi now gay needs some help place I have a 94 G30 cut-away M/H with 350 engine.  It is running rich so I checked for O2 sensor, but it doesn't have one.  The manifold is not drilled for an O2 sensor, the Y pipe has no place for one.  There is a wire that I believe  is for an O2 sensor, but no sensor.  Haven't owned very long and someone had removed the catalytic converter.  Shouldn't this van have an O2 sensor?  It does have a TPI fuel system.  Any help appreciated  Thanks  

Post Reply
waynep712222
I have an SS396 tatoo
Posts: 251
Joined: 03/13
Posted: 07/10/13 09:36 PM

don't you love people who don't understand how it works.. so they disconnect it and throw it away..  they then wonder and cuss technology as it never works... lets throw all this fuel injection crap away and toss a vintage carb on it..


i hope that you don't plan on registering it where you need to pass smog..

a few things... almost every muffler shop will have weld in oxygen sensor bungs..  but their is an issue.. some locations have rules against working on exhaust systems that have had the cats removed.. so.. you might want to find a small independent shop..    or buy a bung and weld it in your self..

manifolds that have threaded ports for the oxygen sensor can get away with a single wire or two wire oxygen sensor..

94 model GM trucks could have a single wire or a 3 wire heated oxygen sensor..   the 3 wire sensors usually are mounted down stream a ways... one wire is a sensor wire.. the shell of the sensor is ground for the sensor circuit..   the other 2 wires are for the oxygen sensor heater circuit.. one side is grounded.. the other is switched 12 volt..

so... the existing oxygen sensor wiring.. does it have a single purple wire ... or a 3 wire connector..

and i am hoping that when you posted TPI.. that you actually ment Throttle body fuel injection..  TBI as that is usually what came on those..    TPI is tuned port injection.. with big curved tubes coming down from a rectangular plenum..  

Post Reply
waynep712222
I have an SS396 tatoo
Posts: 251
Joined: 03/13
Posted: 07/10/13 09:43 PM

warning.. please check the EGR System for operation..   please hook up a vacuum gauge with a tee at the end.. between the hose and the EGR valve so you can monitor vacuum signal to the EGR valve..

if they disabled it.. you MAY experience pinging and short engine life..

lastly.. when you have the inner cover off the engine compartment..  pull the distributer cap and rotor.. look straight at the top of the distributer shaft below the first layer thats riveted on.. make sure the almost black layer is not cracked..  its a magnet.. when the magnet cracks from thermal cycling.. it can effect how the engine runs..  you will also want to examine the sides of the coil winding for signs of high voltage leakage..  that is another failure point on TBI motors..  

Post Reply
mtgtool
I love my Chevy Chevette!
Posts: 3
Joined: 07/13
Posted: 07/11/13 04:37 PM

Thank you for your response,  I guess the only thing I can do is drill and tap the manifold for a 1 wire O2 sensor.  

Post Reply
waynep712222
I have an SS396 tatoo
Posts: 251
Joined: 03/13
Posted: 07/11/13 05:54 PM

looks like the sensor bung is on top of the Y  ... this picture is of the bottom of the head pipe assembly...






you should be able to get an oxygen sensor bung installed in the Y for cheep at some muffler shops...

if it really is gone..

i took a look and your application actually uses only single wire oxygen sensors installed at the y..  

Post Reply
mtgtool
I love my Chevy Chevette!
Posts: 3
Joined: 07/13
Posted: 07/11/13 06:40 PM

I will look tomorrow  to see if there is a place for the sensor in the Y pipe, but I am not sure if the O2 sensor will stay hot enough without the catalytic converter at the Y pipe.  The wire I see is white, not purple. Thank you again for your help.  Mike  

Post Reply
waynep712222
I have an SS396 tatoo
Posts: 251
Joined: 03/13
Posted: 07/11/13 10:14 PM

the only wire i see as being white seems to be the TACH wire..
this is a 94 chevy truck diagram.. not a van.. but it should really be the same..


0996B43f80231a12  

Post Reply
waynep712222
I have an SS396 tatoo
Posts: 251
Joined: 03/13
Posted: 07/11/13 10:26 PM

do you have a printer for your computer..

do you have an OBD1 scan tool???

Scandatagm

there are more than codes in OBD1 GM systems.. with a scan tool.. you can do amazing things..

there are a bunch of versions of these that can be found online. USED..

Otcmonitor4000e

Otcgenisys

Mt2500snapon

Cp9110actronobd1scantool


not all of these will read the 94/95 GM obd1 data streams..

Autoxrayezlinkscanner  

Post Reply
TO TOP