1998 Sonoma SLS 4x4 4.3 Auto P0404 Code

[jaycowen]

Hello,
I have a 1998 Sonoma SLS 4.3 auto, 4x4, W style engine with 150,000kms,
I have been recently been having issues with the truck surging, revving up & down slightly & is very sluggish. I put it on a INNOVA 3130 scanner & the code that came up was
P0404
Exhaust Gas
Recirculation Control Circuit
Range Performance
The P is power train, 0 is Generic, 4 is Aux Emission Control System but I'm not sure of the 04 which is the location. I also have all of the freeze frame settings at the time of the code if needed. Are there any sites etc that break down the generic code more so than the scanner. I also took a laser thermometer to the cat. converter & it was 30 to 50 deg F in the difference from the front of the cat to the rear of it.

I’m looking for some direction as to what it might be or repair tips. Any help is greatly appreciated.

Thanks in advance, Jay

[jaycowen]

I figured the code out ot be the EGR valve & I'm going to remove it to clean & inspect it. Will post futher. Still oopen to suggustions though.

[jaycowen]

I removed the EGR, it & the ports were pretty clean from what I could see . There was a little carbon around the plunger but moved okay. With the key on I had twelve volts at the connector. I put twelve volts to the valve while it was out of the truck & it opened & closed okay. Not sure if this was the issue or not. I eased the code & will now road test as well as re-scan. Any suggestions?

[MT-2500]

It is dangerous to computer stuff to apply 12 volts to it.
404 is a egr valve open pintle position code.
Was there any carbon or a carbon ball under the pintle/plunger?
Clear code and see if it comes back after driving.
If so post back for more help.
MT

[jaycowen]

Good day, Away for a few days, now back to the truck issue, very sluggish hardly pull it's self, causing the trans to heat, put on scanner had P0404, then a P0101 Mass or Volume Air Flow Circuit Range/Performance, then 2 more P0404. Going to clear & take a short test drive again as I wasn't driving at the times of the codes. MAF code seems weird?? Ports on manifold looks good from whait I could see, plugged farther in? I was told to pour intake cleaner in & let it set. Little errie of that. I only used 5 volts on the EGR.

Erased the codes & went a half a km down the road & it wouldn't make it over 20km/h or over 1000 rpm. Coded misfire on no.4 cyl. It had 100psi & plug & gap were fine. Now that the truck is getting worse it seems to be giving more nusicence codes. Whatever the issue is it is definately getting worse. Puzzleing how it can't pick up on it's rpms. It was suggested that the crank sensor when going bad could do it & still not code.

[old_master]

Have you checked fuel pressure?

[jaycowen]

I went back to my gut feeling on the cat. converter this morning & unscrewed the 02 sensor at the Y, went for a drive & was back up to 90-100 km/h with just slightly higher RPM's. I guess it backed up enough to stop the EGR from seating & caused the MAF to code because it couldn't get enough air in. Went to the local muffler shop & they cut it between the flanges so it could still be removed if needed, welded in an aftermarket. $180.00 later I was on the road. It may have taken a little longer but I learned a couple of new tidbits & saved some cash. Thanks for the help; I'll definitely be using this site in the future.