SES Codes 0300, 0141 HELP Again PLease

You guys have been great. Now I have another problem.(of course)
My 97 blazer is running rough it idles fine but when accelerating it hesitates and only stops when I apply the accelerator. I am getting codes 0141 O2 sensor heater circuit malfunction ( bank 1 sensor 2 )
which sensor is this code refering to ?
Also I am getting code 0300 Random/Multiple Cylinder Misfire Detected.
What could cause this problem ? how can it best be checked and corrected ?
Since this problem started I have changed the fuel filter and cleaned the EGR Valve in an effort to correct it and it is still not corrected.
any help[ from one more experienced than I will be appreciated

:screwy: thanks

I also checked the fuel pressure it is fine.

This is a new engine in this blazer.
new plugs, wires, rotor, TPS, IAC, both coolant temp sensors, and IAT sensor. I am hoping that the problem is from bad fuel. But when I filled it up on Friday it did not act up until the next day, after I had driven it for appx. 75 mi.
Somebody help me please this dam thing is nickling an ddimming me to death and nothing costs a nickle or a dime.

Thanks

Sensor bank one is the drivers side or remember the side where #1 cyl is. Sensor 2 is the one after the cat. The random misfire can be alot of things. Always start with the basics and make sure everuthing is correct.

bank 1 sensor 2 is the O2 sensor just before the cat.

Also, did you do a full tuneup lately?

Yes New Engine, most sensors on top.
I think it may be bad gas took it for a ride and filled back up and added a can of sea foam fuel additive and codes cleared, ran fine then died a few hours later. Sent it to a a real mechanic. Might be the igntion module. I will let you know what comes of this latest prob.

Sorry bank 1 sensor 2 is after cat....bank 1 sensor1 is precat.

Sorry bank 1 sensor 2 is after cat....bank 1 sensor1 is precat.

Please don't post unless you know what you are talking about.

He has a 1997 which bank 1 sensor 2 is the sensor just before the cat.

The is FACT.

I am sorry that you do not know what you are saying bud. I am a certified mechanic of 30 years and have my own shop of 16 years now. Sensor 2 will always be after the cat. Sensor 2 monitors the cat on all vehicles. The only thing that changes from some engine is where no#1 cyl is. And bank 1 will always be with the cyl bank #1. Which is always seen as the head farther to the front for people who need the extra help to remember. And sensor no#1 is always before cat and that can be in the pipe or exhaust manifold.
Now get your FACT right!

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Check theses guys out.
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I am sorry that you do not know what you are saying bud. I am a certified mechanic of 30 years and have my own shop of 16 years now. Sensor 2 will always be after the cat. Sensor 2 monitors the cat on all vehicles. The only thing that changes from some engine is where no#1 cyl is. And bank 1 will always be with the cyl bank #1. Which is always seen as the head farther to the front for people who need the extra help to remember. And sensor no#1 is always before cat and that can be in the pipe or exhaust manifold.
Now get your FACT right!

Tell me this then, where is the Bank 1 Sensor 3 then? Or where is Bank 2 sensor 3?

Are they in the tailpipe?

I think the problem was solved.
The sensorcodes were from a the engine misfiring that I assume was due to to factors 1. from bad gas. 2. From a screw coming lose in the distributor. I put a can of sea foam fuel additive in the tank and it ran great then the lose screw arched in the distributor and screwed everything up. I had the parts replaced and everything seems to be running fine now. I am keeping my fingers crossed. Again thanks for your help

Tell me this then, where is the Bank 1 Sensor 3 then? Or where is Bank 2 sensor 3?

You know that is a good question. Considering I have yet to see a sensor 3 as of yet. And my GENISIS Scanner 2002 domestic, 2003 Asian.

Now why it so hard to understand bank 1 is always the side where cyl 1 is located. So bank 2 must be the other side.

Sensor 1 either bank monitors the engine.
Sensor 2 either bank monitor the cat.

Sensor 3, well like i said got me there.

But if there is a sensor 3 I am going to guess in the pipe, must be after 1 & 2.

Sensor 1 will be in manifold or the pipe just after manifold but before the cat.

Sensor 2 will be in the rear of cat or in the pipe just after the cat.

Now you could at times only have 1 sensor 2 because of single exhaust.

But if they use 2 cats on the car then they will use 2 sensors, one in or behind each cat.

Now I know that the new car are making changes with o2 sensor and people are going to cry when they have to pay the newer prices. Since I have an Auto Repair Shop I don't work much on the 2003 and up, only because most are still under warranty with the dealer.

I continue my training with EAST TRAINING,& CTI.
And my employees.

Bank 1 is driver's side
Bank 2 is passenger side.

There is a Sensor 3.

What are the codes P0143-P0147 for then?

They are for the post CAT O2 sensor on 1996+ 4.3L engines.

I really don't know why you are arguing this, you say it doesn't exist but every shop manual and repair guide has them for our trucks.

You know I can stand my own ground here.
And you act like you are the ace here.
Bank one in this case is drivers side. But my response also was to help anyone on any car to understand soemthing you don't about. Now I know He doesn't have a Ford but on Fords bank 1 is passenger side, simply because that is where no1 cyl is. So why is letting people have a understanding that can help them with any auto out a problem for you.
http://www.asashop.org/autoinc/june2002/techtips.cfm
Now I will say again, I think you are telling the person wrong as to which O2 he needs to replace.
I will answer anyone's question that I am able to. I do this everyday for a living. And if you think I am wrong show me so we can learn. But do it in a manner of a moderator.

Let me see if I can clear this up. You guys are talking about different things.

rksnc is talking about a normal oxygen sensor system, with three sensors and single exhaust pipe. This is the same one that I have and everyone else that I have seen. This system includes:

One sensor just below the driver's side manifold - Bank 1 Sensor 1
One sensor just below the passenger side manifold - Bank 2 Sensor 1
One sensor just after the cat - Bank 1 Sensor 2 (The proper way to refer to it) or Bank 2 Sensor 2 (although not the proper way to refer to it this is sometimes used.)


BlazerLT is talking about a system that some of these Blazers are rumored to have. (I have yet to see one, but it has been mentioned on here several times) The system he is talking about would consist of 4 oxygen sensors:

One sensor just below the driver's side manifold - Bank 1 Sensor 1
One sensor just below the passenger side manifold - Bank 2 Sensor 1
One sensor just before the cat - Bank 1 Sensor 2 aka Bank 2 Sensor 2
One sensor just after the cat - Bank 1 Sensor 3 aka Bank 2 Sensor 3

All that being said...I believe the rumor about some Blazers having 4 sensors is just that...a rumor. The only systems (to date) that I know of having 4 sensors would be those with dual exhaust. These systems consist of the following:

One sensor just below the driver's side manifold - Bank 1 Sensor 1
One sensor just after the driver's side cat - Bank 1 Sensor 2
One sensor just below the passenger's side manifold - Bank 2 Sensor 1
One sensor just after the passenger's side cat - Bank 2 Sensor 2

I should add... the references to which side of the engine is bank 1 and bank 2 is based on GM design.

It is not a rumour or they would not have codes to dilineate that sensor being there.

It is no a rumour that several people here have 4 O2 sensors.

Please stop treating it like it is an urban legend or something.

I could be wrong about it being a rumor, that is why I didn't say you were wrong. I'm just saying that it has been said here many times, but I haven't seen anyone yet that had 4 sensors.

I could be wrong about it being a rumor, that is why I didn't say you were wrong. I'm just saying that it has been said here many times, but I haven't seen anyone yet that had 4 sensors.

I have seen many people who replaced all four sensors.

The manifold O2 sensors check the reading coming off of the two banks.

The one before the cat is for the air/fuel ratio and the one after the cat is a catalyst monitor and is also used for long term fuel trim.