hello, i am stumped with my obd 2 blazer.i have been recieving a t.c p0172 for sometime now, every so often it would effect performance but very randomly.now i was out shopping, came out started the engine and right away it shut down.tried to start it and it sounded like it skipped timimg. went and rented a code reader and gave me two new codes the p1406 and p0300. the p1406 says mftr. code, so i assume that means take it to the shop, problem i am a home mechanic trying to save money and want to solve this myself?hellp please.


scott

 

Welcome.
What does the first code mean, even in codese? I don't have them memorized.

 

If you want to know what the codes mean follow this link:

http://www.iequus.com/obd_def.asp

 

Well, I'll say this much. I am stumped by the reasoning that says you give us a code? Yes, I can look it up. Nice post to go look it up at too. I also have the book for the 95. Happen to own one. But why not tell us what the code means so we dont have to open our own information sources to check out what you mean to begin with.

My computer room has three puters and I can certainly go to other sites at the same time to source information. I can also go to the other room and read my manual. Helping as best as I can turns into a real work when I have to go through all of that.

Nothing hardtail meant here, just trying to get on the right track.

P0172 Generic System Too Rich (Bank 1)

P1406 GM EGR Valve Pintle Position Circuit

P0300 Generic Random Misfire Detected

I see P1406 as actually meaning you need to check for an egr problem. Maybe a sticking valve or dirty causing sluggish behavior. Had the same problems myself. Intake can be cleaned. Sometimes this is all that is needed. Check out some "seafoam" at the parts store and try it. It goes into the intake via the pcv valve in this case. At least thats how I did mine. Sometimes an egr may need replaced, but these things are tougher than you think. If something needs replaced it may well be the eletronics right in front of it. Used to be called an egr vacuum solonoid, but cant remember if name changed. Ours may be all electronic now also. A solenoid may not exist any longer.

As you can see, I have not gone to my book and the car is not here. All we can do is our best at the moment.

The misfire is being caused. Not the reason.

The system too rich may actually mean something but could be caused by something as simple as a O2 sensor. Those may be taken off and cleaned. I really think it is also being caused, not the cause itself.

 

That was unnecessary... He may not know what they mean, nor know where to look for the meanings. If it is too difficult or time consuming for you to *help*, then don't. You don't need to put the guy down for only posting the codes. Often the descriptions recieved from Autozone or Advanced are off anyway.

A MUCH better way of handling this situation (if it bothered you - which it obviously did) would be to point to the MANY different resources that will give the meaning of the various codes.

Now onto the codes. All of these codes could be caused by a malfunctioning egr valve. Clean/repair the valve first and clear the codes. See what pops back up.

 

^^^ I'm wiff stupid.^^^^

Do what swartkk said. You may find carbon buildup on the EGR. You should be able to push the pintle w/ a screw driver and it should fully extend when you release it. If it stills throws a code after you cleaned it, a new one might be needed.

 

hello, thankyou for the advice.sorry about the lack of info. i hope i give enough this time.when i relized the p1406 code was the egr valve pintle myself i went ahead and spent the 100 dollars on a new egr valve.that did not help. i know abou the carbon build up inside the intake and that only hinders the running of the engine,i had that problem about a year ago and cleaned the intake watching out for the plastic clips that can be broken off with the breeze of the wind. i have a starting problem, there is no firing going on.it totally does not sound right when the engine cranks, sounds like it is going faster than it should, pointing me to a timing problem.i have the haynes repair maual and i was reading about what controls the timing for the computer, and i was going to replace the crankshaft sensor next?or could it be a fuel problem like it isn't getting any?about a year and a half ago i replaced the fuel pump.now when i did this i ran into the fuel lines being rusted to the sendind unit.my cheap *** cut mthe lines and bought tubing and double clampd the lines back on.well i damaged the sending unit and my fuel gauge does not work and for the year and a half i go by mileage for refueling(sucks but i am cheap).i am about ready to replace the s.u. for the 250 dollars to be on the safe side.i guess instead of saying cheap i should hav said that i macyvered the fuel lines.haha. well that is all i can think to tell right now,i hope i gave enough if not too much info.plz help me i hate not having a 6 cylinder to drive, inline fours suck!


scott

 

How about the TPS? Did you remove it and test it? I think the manual will give the ohmatic tolarances for ya. Good luck.

 

{edited to ask 4lowlife or anyone; not sure what a TPS is, please enlighten. grassya$$
This is from the SI software:

DTC P1406 Exhaust Gas Recirculation (EGR) Position Sensor Performance

DTC P0172 Fuel Trim System Rich

DTC P0300 Engine Misfire Detected

Did you by any chance do anything related to an Alarm system lately? I found this and will post the info I have on it. If you need any related info to the other DTC's, infomr me and I will be glad to help you with any information you post, (if I can, and will be glad to give back for what I have received from here) Here is the post:

#02-06-05-004A Info - Misfire DTCs P0300, P1380, P1381 and Catalytic Converter Damage Due to Installation of Alarm Systems - (Jan 9, 2004)
Info - Misfire DTCs P0300, P1380, P1381 and Catalytic Converter Damage Due to Installation of Alarm Systems #02-06-05-004A - (Jan 9, 2004)
Misfire DTCs P0300, P1380, P1381 and Catalytic Converter Damage Due to Installation of Alarm Systems
2004 and Prior GM Passenger Cars and Light Duty Trucks

2003-2004 HUMMER H2

2004 and Prior Isuzu Light Duty Trucks

This bulletin is being revised to add the 2004 model year and include specific DTCs in the title line. Please discard Corporate Bulletin Number 02-06-05-004 (Section 06 - Engine/Propulsion System).

General Motors Engineering, in an effort to determine the root cause of catalytic converter damage, has determined that aftermarket alarm systems incorrectly installed in vehicles have the potential to cause misfire codes and damage to the converter. These alarm systems use a circuit interrupt which utilizes the ignition circuit on the vehicles.

These alarm systems utilize mechanical relays and normal vehicle movement can trigger these relays to engage and disengage the ignition circuit while the vehicle is in motion. These disruptions of the ignition circuit, which occur in milliseconds, may cause more fuel to be commanded. Over time, this dumping of fuel on and off again can cause misfire codes and ultimately damage the converter assembly.


Important
Engineering could not identify any alarms that utilize solid state circuitry that would eliminate this concern. Because of this, it has been determined that all alarm systems must be routed through the starter circuit in order to avoid this condition.


Dealers must be aware of this issue and take note of the wiring on vehicles with alarm systems that come in for repair, particularly for catalytic converter damage that seem to have no known root cause.

 

Hope you actually cleared the codes. Major item I forgot. On a lot of older blazers and jimmies its the negative to remove. On the later ones its the positive. I always remove both and am seldom wrong.

As I originally posted, NOTHING hardtail meant by my comments. Perhaps being direct is not a positive factor in my life, but its my life, right?

Have you checked the coil, rotor, cap. One little rotor problem can cause all this.

Darn I wish you had not spent that hundred bucks, eeeks. Those things are tougher than that.

Question. And I will get grief for this too.

1. Is exhaust in good condition including cat?
A. Any leaks close to the engine will give it fits.
a. This includes such things as donuts?
b. Any hole before or just after cat.
c. On either side but most likely passenger header, or crossover pipe.
d. Custom exhaust work?

2. Is fuel being deliverred?
A. You mention rubber hose?
a. Pinched or collapsed/collapsing
b. Clamped rubber hose? Are clamps still tight? You might add air into the system, funky.

3. Fuel system rich may change your timing.
A. Brings me back to clearing codes.
B. Carbon buildup will cause not only code but O2 sensor problem.
a. O2 sensor can cause the same effect. It can make a rich engine. Only one bank at a time. Ours do not have the third O2 sensor, or mine doesnt. In other words, a funky O2 sensor can actually cause rich. Rich can cause timing changes. Or visa versa. Rich for real can cause dirty O2 sensor. Too rich for too long can mess with egr and carbon buildup in lotsa places.


Use the cleaner I mentioned, check your plugs. Even a silly loose plug wire can cause this stuff if left long enough. Misfiring wires that get wet are also a subject that can cause this. How old is tuneup? Did you use real 8 mm wires or some cheaper ones? Often, money is not wasted here on good ones. Heat range of spark plugs?? Correct? Gap is right?? Check when you pull a couple. Often home mechanics trust the way they come in the package and dont check. They pack them for certain models, but yours may not be the one? If you buy Delco plugs, they should be close.

Lotsa other things, write back.