97 Lumina EGR Valve and O2 sensor Question?

[gixxeracer87]

When I had it off earlier I did start the car up. I expected it to be loud with the exhaust being open, but it wasn't. I checked it and it was puffing so if it is blocked, it's not completely blocked. I didn't plug the EGR back in to see if it moved. I'll try that. I found a junk yard and bought another EGR for $45. The valve is freely moving on that one too. I'm going to go back up to my work and try and get all that fluid out, and try plugging in the EGRs to see if they move, and see what happens of that. I got a bunch of fluid out earlier today, but it just kept creaping out so I just kinda quit. I'll try to get it all out this time.

[gixxeracer87]

Ok I'm at work now, and I took it off again, and the yellow stuff hasn't made it back into the EGR, so I'm guessing that it's not opening up... I plugged it in and started up the car and reved it up, and the valve didn't move. I plugged in the used one I just bought it it didn't move either. I'm going to go try and see if the wiring is ok. What do you think could be wrong?

[gixxeracer87]

I don't know what I was thinking before. It is pretty loud with the EGR off. I looked at the wiring and I can't find any thing wrong. But I didn't take off all the conduit. If the valve is supposed to move when I rev the engine, than I don't know what could be wrong, unless the used EGR valve I just bought is bad also. I'm kind of at a loss on what to do.

[j cAT]

Originally Posted by gixxeracer87

I don't know what I was thinking before. It is pretty loud with the EGR off. I looked at the wiring and I can't find any thing wrong. But I didn't take off all the conduit. If the valve is supposed to move when I rev the engine, than I don't know what could be wrong, unless the used EGR valve I just bought is bad also. I'm kind of at a loss on what to do.

I just read all this info on your problem.. if you can start engine with EGR off and it will not stall the EGR port to intake manifold is plugged... but I also believe that coolant is getting into the combustion chambers causing the other codes also the exhaust will be very wet/water steam etc if this has coolant entering the combustion chamber as well as very white spark plug tips.....try to use coat hanger to clean out the intake egr port from blockage with this open engine should stall [a good thing] as this goes to engine vacuum....may have to remove throttle body to clean all this...green antifreeze will damage O2's..........so fix coolant problems before replacing O2.........intake manifold internal crack/leak very possible......

[gixxeracer87]

Thanks j cAT.
I checked the resistance in my spark plug wires and they were too high so I changed them out and now it doesn't misfire any more (which was my main goal). I completely cleaned out the yellow gunk out of the intake and put the used EGR valve on and drove about 10 miles and took it off and checked it. there wasn't any thing in there. I'm going to drive it to work tomorrow and check it again. I'll try to clean it out with a coat hanger too to make sure it's not clogged. If it is leaking antifreeze could that just be the intake manifold gaskets? That's pretty easy to replace (I think), just more money. I'm going to try and clear all the codes and see what codes come back. I was told I just have to disconnect the battery for a minute to clear the codes, is that correct? Thanks for all your help guys!!!

[j cAT]

Originally Posted by gixxeracer87

Thanks j cAT.
I checked the resistance in my spark plug wires and they were too high so I changed them out and now it doesn't misfire any more (which was my main goal). I completely cleaned out the yellow gunk out of the intake and put the used EGR valve on and drove about 10 miles and took it off and checked it. there wasn't any thing in there. I'm going to drive it to work tomorrow and check it again. I'll try to clean it out with a coat hanger too to make sure it's not clogged. If it is leaking antifreeze could that just be the intake manifold gaskets? That's pretty easy to replace (I think), just more money. I'm going to try and clear all the codes and see what codes come back. I was told I just have to disconnect the battery for a minute to clear the codes, is that correct? Thanks for all your help guys!!!

that was good you check wire resistance and also check new wires as they also i found can be bad...the codes clear just remove negative battery lead for 5min... that should be long enoungh...if the egr ports are plugged the engine should start pinging when it gets to normal operating temp...and ecm may throw a code....

[jeffcoslacker]

Holy carp! How did I forget that? I'm losing it.

If you take that EGR off again, check for vacuum on the intake port side...he's right, it shouldn't want to run with a wide open vacuum leak like that...if it does, that passage is blocked...I was getting to that when I said "if it will run like that", and then totally dropped the ball...sorry...

The engine may have to be fairly warm to see EGR move...I believe it is disabled until the ECM sees operating temperature...try letting the motor warm up real good and then remove it real quick and give it a go...the more load, the more EGR is needed, also try torquing it up in gear with throttle and seee if it moves...

Exhaust should blast outta the pipe side just as if it was a little exhaust pipe, no restriction...

[gixxeracer87]

I took off the negative battery cable for about 30 minutes. While I was waiting I took off the EGR (again lol) and shoved a coat hanger in the intake as far as I could. Only got it maybe 3 inches because of all the bends. Pulled it out and it had some gunk on it, but I don't know if I just scraped that off the walls or if I hit the clog. When I had if off and running before it seemed to be running like normal, but I haven't noticed any pre-detonation. But then again it's only about 5 miles to my work, and it's rather cold out side. I may not be getting it to operation temperature. I didn't start it up with it off this time because I was trying to clear the codes... when I got it all back together the check engine light was still on, and I took it to AutoZone and it doesn't look like I got the codes cleared. The guy there said to completely remove the battery for 24 hours. (I read some where, it said to remove one cable for one minute and they would be cleared). He refused to clear them with his scanner because of liability issues. I can't really take it off for 24 hours because this is my only transportation at the moment. You guys have an idea? O and I think I forgot to mention earlier that I pulled the #6 spark plug and it was white...

[jeffcoslacker]

You can't clear OBDII codes without the scanner.

jCAT was right, it should suck so much air through the manifold passage that it shouldn't be able to idle with it open...that was the point I meant to make, but got sidetracked originally. I'm glad he pointed that out.

So you are still clogged on the intake side...

You probably won't detonate without EGR, you have a knock sensor that retards the timing to kill that before it's audible...the old ones without it would ping with the EGR inop, true...

That's why I was asking if it was breaking up on acceleration, or just laying down...thought the timing might be being retarded and making it flatten out...

[j cAT]

I think I forgot to mention earlier that I pulled the #6 spark plug and it was white...[/quote]


If all the plugs are normal color light brown and one is white this is the cylinder that is getting coolant in it.... probably head gasket but possible intake manifold.....

[gixxeracer87]

I was in a hurry so I just pulled that one plug. I'm not looking forward to pulling the rear plugs. Any ways... You guys are Awesome!!! I found a clog in the intake manifold, and I think I got it cleared out. Had to rip off the air cleaner and all that jaz to get to it, but I think it's working now. I guess I got to go sweet talk a shop into clearing the codes for me. Do you think I still need to change the rear O2 sensor or do you think that clog was causing that too?

[jeffcoslacker]

Like I said, the o2 bank of the cat may have been depleted and unable to get a supply of oxygen due to the clogged EGR...this makes the cat partly ineffective, and might account for the lack of activity seen from the rear o2 sensor...

The heater grid fault still bothers me though, but see what happens now....

[j cAT]

Originally Posted by gixxeracer87

I was in a hurry so I just pulled that one plug. I'm not looking forward to pulling the rear plugs. Any ways... You guys are Awesome!!! I found a clog in the intake manifold, and I think I got it cleared out. Had to rip off the air cleaner and all that jaz to get to it, but I think it's working now. I guess I got to go sweet talk a shop into clearing the codes for me. Do you think I still need to change the rear O2 sensor or do you think that clog was causing that too?

now that this intake clog is opened i would check to be sure by removing the egr....then go and disconnect battery for 5min and then go to auto zone for the codes and then report to us what the dtc's are....

[jeffcoslacker]

Originally Posted by j cAT

now that this intake clog is opened i would check to be sure by removing the egr....then go and disconnect battery for 5min and then go to auto zone for the codes and then report to us what the dtc's are....

That won't clear OBDII codes...It will put the radio into security lockout, and he'll have to go through that headache...

[gixxeracer87]

Originally Posted by jeffcoslacker

That won't clear OBDII codes...It will put the radio into security lockout, and he'll have to go through that headache...

Yeah, I tride disconecting the batery and then going to AutoZone, they were all still there. BTW, does O'reilly's check the codes for free too? I'm sure the people at AutoZone are getting tired of seeing me LOL.

I took the car by a shop, and they said that it would reset itself in time if nothing is wrong. I don't understand why it has to be so difficult...

Anywho, I'm a bit concerned because now the car doesn't start right up like it use to. I don't know if it's related to what I've been doing, but now sometimes it has to crank over a few times, and then when it does start, it kind of lags for a few seconds, like it's misfiring. I'm guessing I might aught to change the spark plugs? I just don't understand because it was running just fine except for the misfire at high RPMs.

I don't know much about O2 sensors, but I'm guessing that the rear one is bad because it's giving the P0141 code about the heater on it. I don't see how that could be related to the EGR. I guess I'll go ahead and replace it when I get some money. Thanks again for all your help guys!