EGR problems
Thread Starter
Staging Lane
Joined: Feb 2016
Posts: 73
Likes: 0
From: Indy
EGR problems Indeleted my EGR a year ago on my '98 Formula and now I'm throwing P0300 and P0405 codes with misfires.
I originally thought it was a bad fuel pump since my fuel gauge started being off at fill ups but the reader confirms exhaust gas circulation low.
Has as anyone else had a similar issue? I haven't had time to dig into it with work being so crazy so if anyone has dealt with it, it could save me a lot of time and money.
I originally thought it was a bad fuel pump since my fuel gauge started being off at fill ups but the reader confirms exhaust gas circulation low.
Has as anyone else had a similar issue? I haven't had time to dig into it with work being so crazy so if anyone has dealt with it, it could save me a lot of time and money.
ive never done this, but i found this - maybe it will help?
https://ls1tech.com/forums/pontiac-f...-problems.html
https://ls1tech.com/forums/pontiac-f...-problems.html
The 405 is solidly a problem with the EGR wiring or sensor, so I'd start there. The 300 is likely a result of the EGR malfunction.
Can you tell that the car is misfiring or do you just see the service light?
Can you tell that the car is misfiring or do you just see the service light?
Thread Starter
Staging Lane
Joined: Feb 2016
Posts: 73
Likes: 0
From: Indy
I can tell it's misfiring really badly. I'm thinking a vacuum leak somewhere from everything I've read thus far. The car completely falls on its face at lower RPM and minimal accelerating power at speed. That's why I thought it was the fuel pump at first combined with the gauge not reading full at fill ups recently.
Im gonna get a can of starter fluid and check for leaks this weekend.
If the EGR valve is failing, that can cause your misfire.
Since you can tell it's misfiring: One thing to try would be to unplug the EGR. This may cause the car to throw other codes, but could clear up the misfire if the engine compensates for the EGR being taken out of the loop. If the car feels better after doing this, it would point more and more to having an electrical problem with the EGR circuit/sensor.
Thread Starter
Staging Lane
Joined: Feb 2016
Posts: 73
Likes: 0
From: Indy
Are you chasing down the misfire problem first or the EGR? The EGR code is an electrical problem with the sensor.
If the EGR valve is failing, that can cause your misfire.
Since you can tell it's misfiring: One thing to try would be to unplug the EGR. This may cause the car to throw other codes, but could clear up the misfire if the engine compensates for the EGR being taken out of the loop. If the car feels better after doing this, it would point more and more to having an electrical problem with the EGR circuit/sensor.
If the EGR valve is failing, that can cause your misfire.
Since you can tell it's misfiring: One thing to try would be to unplug the EGR. This may cause the car to throw other codes, but could clear up the misfire if the engine compensates for the EGR being taken out of the loop. If the car feels better after doing this, it would point more and more to having an electrical problem with the EGR circuit/sensor.
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Sorry. I read your post and it processed as you replaced the EGR. 
I guess you've had the EGR code ever since your delete?
Wells has had some great live tech sessions and has posted a number of diagnostic videos on P0300 over the years. Here's just a few:
https://www.aeswave.com/blog/The-uSc...nar-bp222.html
http://www.wellsve.com/videos_p0300_diagnostics.html
The problem could be anything. ^ Wells sells electrical and sensors, so it's probably no surprise that they focus on electrical causes - but (if you have the right tools), those are pretty easy things to check.
I guess you've had the EGR code ever since your delete?
Wells has had some great live tech sessions and has posted a number of diagnostic videos on P0300 over the years. Here's just a few:
https://www.aeswave.com/blog/The-uSc...nar-bp222.html
http://www.wellsve.com/videos_p0300_diagnostics.html
The problem could be anything. ^ Wells sells electrical and sensors, so it's probably no surprise that they focus on electrical causes - but (if you have the right tools), those are pretty easy things to check.
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Thread Starter
Staging Lane
Joined: Feb 2016
Posts: 73
Likes: 0
From: Indy
No I didn't tune it out. The codes been there ever since and hasn't had any issues until now. I need to get under the hood and see what's going on.
Thread Starter
Staging Lane
Joined: Feb 2016
Posts: 73
Likes: 0
From: Indy
Welp, Replaced both 02's and it cleared the code but the engine is still really sluggish. Checked 7/8 plugs (you know why) and a couple were slightly caked but not too bad so I replaced those anyway. Did find a loose wire on 8 but after re-plugging it, no change. Also took some carb cleaner to try and get any type of surge or bogging and got nothing from that.
Gonna put a fuel pressure gauge on it later but wanted to take a break before I set it on fire. If that's not showing anything, I guess I'll start pulling the intake to check for oil build up and check the springs and push rods under the valve covers.
Gonna put a fuel pressure gauge on it later but wanted to take a break before I set it on fire. If that's not showing anything, I guess I'll start pulling the intake to check for oil build up and check the springs and push rods under the valve covers.