Allrighty to begin with I have a '96 Blazer 4wd 4.3 v6. I have been reading for the past week here and other places and finally have had a reason to use the new scan tool I found at a yard sale ( Actron cp 9190 if anybody's interested. was it worth 25 bucks? maybe when I have it all figured out.) Well I guess I'll start with the symptoms the patient has. Little power on acceleration, not much power going uphill and occasionally wants to misfire, if going down the road (found this out accidentaly btw) and the wife knocks the shifter into neutral lots of black soot/smoke comes out the exhaust, starts fine, and idles ok with a little miss. Now for the DTC I have been getting on the old girl. po134 o2s circuit no activity detected 1/1 (bank 1 sensor 1? ), p0171 system too lean bank 1 , p1133 ho2s 1/1 insufficent switching , and a p0300 which is the dreaded random/multiple cylinder misfire detected. Here's some freeeze frame data from the p0300; MAF 5.42 , MAP 26.6, Coolant 192 deg, st ftrm1 50, lt ftrm1 18, st ftrm2 2.3, lt ftrm2 0.8, fuel systems 1&2 closed loop, that's all there is on that. I have had a code saying there was a problem with a heater on an o2 sensor and keep getting the lean code for that engine bank 1 (btw bank 1 is the one on the driver's side right? never can remember), We had sold this vehicle to my father in law a few years ago and just before he died a month ago I put in a new catalytic converter and 2 o2 sensors for him, the cat was in bad shape and the sensors were a why not kind of thing for him. (mother in law gave the thing back to me and the wife since she doens't know how to drive) I saw on the exhaust higher up what look to be two more sensors just outside the exhaust manifold kind of on the down pipes. Should i give these a go? I'm going to change the ignition stuff tomorrow (plugs, wires, etc) and have already replaced the vacuum lines on this particular beast. I will probably change the fuel filters some time this week as well. Any other suggestions? I'm running out of relatively cheap ides and the wife gives me that look (you know the one ) every time it hiccups going down the road. hopefully I can get this thing fixed and quit beating my head on a rock thanks in advance and it is much appreciated. Sorry to be so long winded, I just hope I have enough usefull info here. Hopefully I can figure a Chevy out before I go nuts.

 

Oh my... That is a mess to read through...

I see the following codes:
P0134 - HO2S Circuit Insufficient Activity Bank 1 Sensor 1
P0171 - Fuel Trim System Lean Bank 1
P1133 - HO2S Insufficient Switching Bank 1 Sensor 1
P030x - Random/Multiple Cylinder Misfire Detected

They all seem to state that there is a problem either with the O2 sensor, fuel supply, or exhaust consistency on the driver side. If you swap the O2 sensors side to side and the codes do not follow the sensor, then the sensor is good. Check the exhaust for leaks which may allow additional oxygen into the exhaust before the O2 sensor, throwing off its readings. Looking at your STFT, it is maxed out which would indicate that the PCM is attempting to richen the mixture A LOT.

 

About to go give it a shot. Thanks for the input swartlkk I'll update as soon as I can.

 

Haha...I know that look. I saw it for quite some time after I first bought mine. If it makes you feel better, I got mine all fixed up and now my wife is shopping for her own blazer =) Hang in there.

Speaking of which. Anyone need a truck?

http://cgi.ebay.com/ebaymotors/ws/eB...#ht_500wt_1182

 

Dude use your ENTER key every now and then

 

I know, train of thought an' all that.

Any tips on getting the middle sparkplug out on the drivers side? I cant get onto it to save my life.

 

disconnect steering shaft and push it back into itself, it collapses

 

Well the job is done. Running good after o2 sensor swap and tune up. drove for a couple hours tonight over hill dale and highway and no codes no troubles. I did get the middle plug changed by calling a freind with smaller hands to get the thing out. cut down an old cheapo box end wrench to clear all the other bits and turned the socket with the cut wrench. Time for a celabratory shot of 1800 reposido.

 

congrats!

 

Glad to hear =)