Well I have finally got my car on the road for this year and I have two engine codes that popped up cruising on the highway. Code 32 & 44, EGR and lean exhaust. I'm pretty positive that the EGR system is also responsible for the lean exhaust code. Although I also have a small crack in the forward manifold. Could this slight crack contribute to a lean condition?
Assuming the EGR is at fault (which I believe it is), what is the best course of action? I have already soaked the in carb cleaner and made sure it moved and visually inspected and replaced the vacuum lines I can see and it is still throwing a code. I've noticed my engine also bogs a bit under load (no burnouts for me). Since I just dropped $500 on tires I'd like to fix this as cheap as possible. Also, I do not own a vacuum pump.
So all that said, if my suspicions are correct, would it be better to try to hunt down the EGR problem and fix it or should I block it off and buy a code eliminating chip off the forum? Is there any real benefit to having it besides better emissions? Is there any benefit to removing it besides aesthetics and less carbon building up in the intake?
Even though the EGR valve moves, it may still be defective. You can test it even further without a vacuum pump. While the engine is cold, remove the vacuum line from the EGR and feel underneath for the diaphragm. Press upward on it and while it's up, cap the vacuum port with a finger. Release pressure on the diaphragm, but keep your fingers in contact with it. If the diaphragm moves downward, it has a hole in it. Replace the EGR valve.
Replacing the O-2 sensor is inexpensive and straight forward. Lean burns can be the result of vacuum leaks in lines, the EGR tube or around gasket sealing areas. You can use a small propane torch to check for leaks. With the engine running, and the torch NOT ignited, open the valve slightly and pass the tip of the torch along vacuum lines and intake mating surfaces. The engine will increase in rpm as you pass by the leak area.
Recently I had my MERA start giving me fits. Turns out the EGR valve actually seperated right where the trianglar piece attaches near the uper valve. While teh engine is cold just get your hand in there and touch things to make sure nothing has broken free...just to eliminate some little things.
the "cheap" fix is to just block the EGR on the exhuast y-pipe & at the intake manifold, and call it done. couple bucks in scrap metal. if you have EGR gaskets laying about, you can use them as a template for the blocking plates. then, IF you have any driveability issues, get a chip done.
the "cheap" fix is to just block the EGR on the exhuast y-pipe & at the intake manifold, and call it done. couple bucks in scrap metal. if you have EGR gaskets laying about, you can use them as a template for the blocking plates. then, IF you have any driveability issues, get a chip done.
Get a chip done.
Otherwise It will still set a code 32. If you block off the ports, the ECM will still try to operate the EGR. If you fake out the ECM (I'm not going to mention how) it will think the EGR is working and will cause the engine to run far too lean and with far too much spark advance. The immediate result will likely be that it will ping (spark rattle.) The long term effect can be burned pistons, etc. Some people get away with it. Some don't. For the cost of an "EGR delete" chip, I wouldn't push my luck.
I vote for fixing the EGR. I've been there twice, and I've fixed it both times. First time, I didn't really have a choice, as I was failing emissions (NOx). Second time, I did have a choice (I didn't live in the same area), and I fixed it anyway. Maybe if the parts were no longer available, I'd bypass it, but for now, the parts are still available. The engine was designed for it. You might be able to get it run just as well without it, but you will be putting out more pollution. I'm not a tree hugger, but I hate getting caught in traffic behind a vehicle that's obviously been modified (because you can hear the loud exhaust), and you can't breathe because the idiot owner only did enough of the mod to make it loud, not enough to make it actually run right.
... I also have a small crack in the forward manifold. Could this slight crack contribute to a lean condition?
Yes. At light throttle air will actually be sucked through the crack into the manifold, and the O2 sensor will report the extra oxygen in the exhaust to the ECM. Of course, a bad O2 sensor can also trigger any of several DTCs.
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Assuming the EGR is at fault (which I believe it is), what is the best course of action?
As phonedawgz has already said, Code 32 indicates a problem in the EGR control solenoid, not in the EGR valve itself.
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So all that said, if my suspicions are correct, would it be better to try to hunt down the EGR problem and fix it or should I block it off and buy a code eliminating chip off the forum? Is there any real benefit to having it besides better emissions? Is there any benefit to removing it besides aesthetics and less carbon building up in the intake?
I say fix the problems; they are both relatively minor.
Benefits: EGR not only reduces emissions, it also improves fuel economy when cruising at partial throttle. EGR is automatically turned off as you approach full throttle, so performance is not affected.
Disadvantages: EGR does tend to foul the intake manifold with soot, but that is mainly an aesthetic problem and does not affect engine performance. And, of course, EGR introduces additional complexity to the engine systems and requires occasional maintenance.
[This message has been edited by Marvin McInnis (edited 07-06-2013).]
For what it's worth I just solved a lean exhaust code in my Fiero. It was also causing light surging/missing while cruising. For me it was my 02 sensor itself.
First we checked for vacuum leaks and couldn't find any. When that was fine we unplugged the 02 sensor and the car immediately idled better. My neighbour connected his scanner after that test and confirmed that the 02 itself was faulty - it was completely dead and alway reporting lean.
New 02 sensor was installed and all was well again. I'm not saying that's your problem, but it is somewhere to look.
A hairline crack in the exhaust manifold may throw the reading off a bit, but I don't think it would throw a code. If it's a sizeable crack it is likely contributing to the lean code. It took a hole in my wife's exhaust to throw the 02 code in her car, although I can gaurentee it was throwing off the air/fuel mix before the code set and I got the chance to fix it (loss of fuel mileage was clear). This was a completely split pipe before the 02 sensor causing her issue.
[This message has been edited by Ry86GT (edited 07-04-2013).]
Recently I had my MERA start giving me fits. Turns out the EGR valve actually seperated right where the trianglar piece attaches near the uper valve. While teh engine is cold just get your hand in there and touch things to make sure nothing has broken free...just to eliminate some little things.
Yep, had this happen to me too. Car ran bad and I didn't catch it right away until I was watching the engine run and finally noticed the vacuum diaphragm shaking around like a bobble head.
Just finished the EGR delete with a Phonedawgz chip. I drove the car around for awhile without changing the chip and no code 32 ever appeared. Could be a problem with the ECM I suspect. There doesn't appear to be a short in the vacuum switch wiring, the only thing outside of the ECM that might cause the ECM to think the EGR was still intact. My upper plenum was pretty crapped up with soot so I am wondering if the EGR was running open when it shouldn't. With the new chip in place, the car runs noticeably better now.
BR's,
Mark ------------------ 86 SE V6 4 speed 86 SE V6 Auto 2008 G6 GT "Street" Coupe 2005 Buick 3.6 Rendezvous 2001 Olds Silhouette (AKA The Band Van)
[This message has been edited by MarkS (edited 07-06-2013).]
Much of the junk inside the intake is from the PCV system. Oil vapors condense and over time, combined with the EGR input, it can really build up. If the EGR valve was running open, you'd know it for sure.
Does NY have emission test at inspection? W/o EGR in working order, might not pass.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
