CODE 1406 --- HELP

[Nicklz]

Ok that might not have been the right code, but what ever the # was it was saying something was wrong with the EGR valve.
Now as I understand that valve allows for some spent exhaust gas to go back into the engine to be reburned....?
Is that right?
Now I delete this code start driving and it comes back on once the car warms up. (which is also when the egr valve is supposed to start circulating from my understanding)
So maybe this valve is stuck?? I really don't want spent exhaust gas going back into my engine, wouldn't it cut power because it's already heated.

Any harm in leaving this "unstuck" someone also told me there was a way to deactivate this valve, which would cause the check enigne light to stay on which annoys the hell out of me. Which I wonder if the previous owner may have done this.

I believe I have a different exhaust anyway due to the fact it's way louder than any other firebird I see driving around.

Any thoughts??

[majeskyb]

The egr valve is a big piece of emmissions hardware on your car. If you live in a state that does yearly emmissions testing, you will need this to be functioning. Although it's from Toyota, the principals behind their operation is the same
EGR info

[98Camaro3.8]

You need to see what the actual code is. If the valve is stuck closed, that's no big deal....lots of people, like myself, block of the EGR completely. If it's stuck open, though, you could have problems idling, etc. Leaving it blocked off really won't do any damage, but it will raise combustion chamber temps (possible detonation issues) and lower gas mileage a bit.

[HBHRacing]

P1406 is just a code for the EGR position sensor. Chances are that you have a bad valve. The sensor is internal in the sensor. it;s a poteniomiter which will send a volatge to the computer based on EGR pintal position. If the actual position if different then the desired position that you will get this code. you can try clening the EGR and passage way to the intake but the only way to see whats going on is to have a shop scan it and driving it.

[Nicklz]

ok i read the whole egr info majeskyb posted. And it raised another question. According to that info it's saying the EGR system is necesssary or you may encounter detonation??

Also I believe the previous owner had installed a 180 degree thermostat, could this not be allowing the engine to heat up enough? (I say 180 degree thrmstat because thats right where my temp gauage goes up to and stays)

[HBHRacing]

not having an EGR system will give you a better chance of detionation, but actualy lower temps are going to prevent that. you should be fine at 180. your will be in closed loop which is the only thing that you need worry about.

[Nicklz]

I owned a turbo charged mr2 before this firebird and detonation always came with the combination of A- too much boost causing high temps and/or B-Gases octane being to low for the boost your running

I don't get it, if I'm not putting the recirculated exhaust gas (higher temp) back into the combustion process why I'd run the chance of detonation.
I'd think with just fresh air and gas into the system you'd run less of a chance of detonation??

As for octane I've been using 87, thats what we always used in my dad's 91 3.1 v6. As for the temp during normal driving it stays right at the 1/4 mark about 180. Sitting still or very agressive driving it can go up to the 1/2 way point, normal??? Because I haven't felt detonation, and how would I know if I had?
With the mr2 you'd get "knock or ping" and the computer would automatically adjust limiting the boost to 1/2 i.e. stopping detonation.
I'm not saying I'm right I'm asking for someone to point out where I'm wrong.

[HBHRacing]

ah. cause you see.. your not putting heat into the motor. your putting cool into it. The exhuat is still cooler then combustion chamber temps, so that cools it some. Then you also have unburnt fuel in the exhaust which also cools the combustion chamber. that is why when the EGR valve is not working or not there you run the risk of detiontion due to HIGHER combution chamber temps. And as you know the higher the combustion chamber temps the more volitile the gas will be and the eiser it will ignite.

[Nicklz]

Yeah I understand that, but isn't the EGR "air" still hotter than outside air? Thats the way my mind was working....?

[HBHRacing]

yes, exhaust air is hotter then outside ambiant temps, but thats like saying takeing a coal ovan that is bunning at 800 degrees and putting 200 degree burning paper inside it. sure it;s hotter then the air but it;s still a lot cooler then the temps inside the ovan. same with combustion chamber temps, they are A LOT hotter then any exhaust gas, especialy since the extra unburnt fuel will be even more cooling.

[Nicklz]

Ok 98camaro3.8 said alot of people block off the EGR. Last question on this topic I promise. What is the benefit of blocking of the EGR (As long as your not detonating)

I'm going to guess at my own question. Since there is a lack of exhaust gas in the combustion chamber, it gives more room for air/fuel mixture resulting in more power? this agian seems logical but i was worng earlier so........am i right this time?

[98Camaro3.8]

EGR is not used at full throttle, so you wouldn't see any improvements at the track. The only benefit may be cleaner intake manifolds. The only reason I blocked it off was because of the headers.

[HBHRacing]

Originally posted by 98Camaro3.8:
EGR is not used at full throttle, so you wouldn't see any improvements at the track. The only benefit may be cleaner intake manifolds. The only reason I blocked it off was because of the headers.

EGR postion is bassed on amount of throttle. at 100% throttle you have 100% EGR duty cycle, so yes it is used at WOT.

Most people block them off when they do not work anymore due to exhaust modifacations. You will not see any more power. The LT1 guys also delete them to get rid of the EGR tube that can warp the intake gasket.

The only problems that you should have are slightly higher engine temps and very very slightly more lean. but it should be nothing that you will ever notice.