Service Engine Soon - 96 Chevy Truck

1996 Chevy Silverado, 5.7L, Service Engine Soon light came on/off for a day or two...now is staying on. I had a local auto parts store perform OBD check and po155 [O2 Sensor Heater Circuit Malfunction
(Bank 2 Sensor 1)] and po175 [System too Rich (Bank 2)] codes were listed. The plugs, wires, rotor button, rotor cap, air and fuel filters and pcv valve have all been changed within the last 3-4 months.
Is this a problem with the O2 sensor(s) or something with the throttle body? Any help with diagnosis and/or solution would most appreciated.
--
Posted using the http://www.autoforumz.com interface, at author's request
Articles individually checked for conformance to usenet standards
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
cookiemonster wrote:

winter. The "book" says to replace them every 30K, yeah right. DO NOT get the "universal" style. Spend a few extra bucks and get the ones that plug right in. IIRC they were $60-65 each online. Make sure you know which plug style you are replacing. There is an in line and a four square type. Mike
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I would focus on the heater circuit first, first check the fuses for the o2 sensor, if ok you must get a wiring diagram to check the heater circuit to the sensor to determine if the sensor itself is bad, most likely this is the problem, there is some chance that may also correct the 0175 problem, when fixed clear the codes and see.

http://www.autoforumz.com/Chevrolet-Service-Engine-96-Chevy-Truck-ftopict122692.html
-
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I had a similar problem on a 96 Tahoe. 5.7L Engine was running rough and the MIL lamp came on. Turned out to be a bad fuel pressure regulator.
Good Luck, TJ

692.html
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"cookiemonster" wrote: > 1996 Chevy Silverado, 5.7L, Service Engine Soon light came > on/off for a day or two...now is staying on. I had a local > auto parts store perform OBD check and po155 [O2 Sensor > Heater Circuit Malfunction (Bank 2 Sensor 1)] and po175 > [System too Rich (Bank 2)] codes were listed. The plugs, > wires, rotor button, rotor cap, air and fuel filters and pcv > valve have all been changed within the last 3-4 months. > > Is this a problem with the O2 sensor(s) or something with the > throttle body? Any help with diagnosis and/or solution would > most appreciated.
I replaced the forward O2 sensors on both sides. That fixed the service engine light. Thanks to Mike, Shep2 and TJ for your input. However, the truck still idles a bit rough. Any ideas? Thanks again for your help! CM
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

yes
what part of 'HEATER CIRCUIT MALFUNCTION' is so difficult to understand ?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"" wrote:
> > > "cookiemonster" wrote: > &nbsp;> > 1996 Chevy Silverado, 5.7L, Service Engine Soon > light came > &nbsp;> > on/off for a day or two...now is staying on. I had > a local > &nbsp;> > auto parts store perform OBD check and po155 [O2 > Sensor > &nbsp;> > Heater Circuit Malfunction (Bank 2 Sensor 1)] and > po175 > &nbsp;> > [System too Rich (Bank 2)] codes were listed. The > plugs, > &nbsp;> > wires, rotor button, rotor cap, air and fuel > filters and pcv > &nbsp;> > valve have all been changed within the last 3-4 > months. > &nbsp;> > > &nbsp;> > Is this a problem with the O2 sensor(s) or > something with the > &nbsp;> > throttle body? Any help with diagnosis and/or > solution would > &nbsp;> > most appreciated. > > > > I replaced the forward O2 sensors on both sides. That fixed > the > > 'service engine light'. Thanks to Mike, Shep2 and TJ for > your input. > > However, the truck still idles a bit rough. Any ideas? > > yes > > what part of 'HEATER CIRCUIT MALFUNCTION' is so difficult to > understand ?
is it necessary that the rear o2 sensor be screwed in . I am missing the caty and muffler. will this cause the engine light to come on. All sensor have been replaced!
--
Posted using the http://www.autoforumz.com interface, at author's request
Articles individually checked for conformance to usenet standards
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"cookiemonster" wrote: > 1996 Chevy Silverado, 5.7L, Service Engine Soon light came > on/off for a day or two...now is staying on. I had a local > auto parts store perform OBD check and po155 [O2 Sensor > Heater Circuit Malfunction (Bank 2 Sensor 1)] and po175 > [System too Rich (Bank 2)] codes were listed. The plugs, > wires, rotor button, rotor cap, air and fuel filters and pcv > valve have all been changed within the last 3-4 months. > > Is this a problem with the O2 sensor(s) or something with the > throttle body? Any help with diagnosis and/or solution would > most appreciated.
I thought I had it fixed.
I replaced the front (before catalytic converter) two O2 sensors since they are the only ones that influence fuel settings/flow. The engine light went off and stayed off for a couple of days. However, it was still idling a bit rough.
Engine light has come back on with code "P0175 System too Rich (Bank 2)". Any ideas what this could be? If it was the fuel pressure regulator problem, wouldnt both banks (right and left) run too rich? Any suggestions or direction appreciated.
CM
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.