CEL & P0441 Code, 98 5.7/350 Runs Rough

[Ol'Jim]

Trying to help brother in law, who is 800 miles away. His truck was running rough, random missing, occasional backfires. He changed plugs, no difference. He took it to O'Reilly, had codes read, kid told him Catalytic Converter was bad. I told him to check the distributor cap for the white "calcium"-looking buildup on terminals, as it is conductive and chunks can fall down into the distributor and mess with the magnetic pickup/sensor. Had that happen on my '88, caused similar symptoms. Anyway, he went to an exhaust shop and spent $360 for 2 new cats, which did nothing to help. This was 4 days ago, now his check engine light comes on, still runs poorly, and Autozone scanned it, came up with code P0441. Is that an Evaporative Emissions system fault? Does the '98 have a charcoal cannister up front, like the older ones did? Thinking this fault has nothing to do with the misfire issue, but maybe the exhaust shop messed up the fuel vapor line? Looking for ideas, thanks!

[MT-2500]

Originally Posted by Ol'Jim

Trying to help brother in law, who is 800 miles away. His truck was running rough, random missing, occasional backfires. He changed plugs, no difference. He took it to O'Reilly, had codes read, kid told him Catalytic Converter was bad. I told him to check the distributor cap for the white "calcium"-looking buildup on terminals, as it is conductive and chunks can fall down into the distributor and mess with the magnetic pickup/sensor. Had that happen on my '88, caused similar symptoms. Anyway, he went to an exhaust shop and spent $360 for 2 new cats, which did nothing to help. This was 4 days ago, now his check engine light comes on, still runs poorly, and Autozone scanned it, came up with code P0441. Is that an Evaporative Emissions system fault? Does the '98 have a charcoal cannister up front, like the older ones did? Thinking this fault has nothing to do with the misfire issue, but maybe the exhaust shop messed up the fuel vapor line? Looking for ideas, thanks!

What kind and size truck?
That code does not show up on code chart.
If it is running that bad it should have more codes.
I would get a good repair shop to put it on a good engine capable scanner.
Post back any codes from a good engine scanner.

[j cAT]

Originally Posted by Ol'Jim

Trying to help brother in law, who is 800 miles away. His truck was running rough, random missing, occasional backfires. He changed plugs, no difference. He took it to O'Reilly, had codes read, kid told him Catalytic Converter was bad. I told him to check the distributor cap for the white "calcium"-looking buildup on terminals, as it is conductive and chunks can fall down into the distributor and mess with the magnetic pickup/sensor. Had that happen on my '88, caused similar symptoms. Anyway, he went to an exhaust shop and spent $360 for 2 new cats, which did nothing to help. This was 4 days ago, now his check engine light comes on, still runs poorly, and Autozone scanned it, came up with code P0441. Is that an Evaporative Emissions system fault? Does the '98 have a charcoal cannister up front, like the older ones did? Thinking this fault has nothing to do with the misfire issue, but maybe the exhaust shop messed up the fuel vapor line? Looking for ideas, thanks!

the problem is the miss fires which if you drive it long enough will overheat the cat converters. with these vehicles if the converters were bad the dtc would show this most times . if they just told him bad converters will cause miss fires then he should not rely on those type employees to diagnose engine issues.

on the miss fires I would measure the fuel pressures and do the fuel pressure test procedure..if that passes then if the vehicle has over 175,000 miles replace the distributor as the bearings fail causing the rotor to wobble...

the 441 would be a leak in the fuel vapor system. can not hold vacuum or pressure when the PCM does the test. bad cap/vapor lines.hole in tank/ gasket fuel pump/vent valve stuck open/line to vent valve off,broken.canister cracked..crap like that !

[Ol'Jim]

Guys, thanks for your input.
I passed it along to him. Sorry for lack of more detail on vehicle when I first posted. He told me last night it is a '98 Chevy 3/4T Ext Cab, 350. He said about the same time it started running bad, it also started smelling "gassy". I asked him if he meant as in an overly rich mixture, or as in raw fuel vapor. He said he couldn't tell for sure, but it is not leaking fuel, and he thinks it is in the exhaust. So this might make sense then, based on what j_CAt posted about DTC P0441. Thinking if there is a vac leak, that would result in lean exhaust, which the O2 sensor would report to the PCM. PCM then would attempt to order up more fuel from injection, which would then result in rich-smelling exhaust?
I told him to check over the vapor canister, the entire length of the vapor lines, including line connections to canister, the purge valve, and the fuel tank, as well as the seal of the gas cap.
If no cracks or apparent leaks, would you suspect the purge valve/solenoid? Can it be tested with a vacuum source? (He is near my home in TX, and I have a hand-operated vac pump there).
Also told him about potential distributor issue with bearings. He said his truck is right at 170K miles, so that sounds like a real possibility. I suggested he put an ohm meter on his plug wires. He has replaced plugs and dist cap.

As always, I really appreciate you guys and A/F for the help.

[j cAT]

Originally Posted by Ol'Jim

Guys, thanks for your input.
I passed it along to him. Sorry for lack of more detail on vehicle when I first posted. He told me last night it is a '98 Chevy 3/4T Ext Cab, 350. He said about the same time it started running bad, it also started smelling "gassy". I asked him if he meant as in an overly rich mixture, or as in raw fuel vapor. He said he couldn't tell for sure, but it is not leaking fuel, and he thinks it is in the exhaust. So this might make sense then, based on what j_CAt posted about DTC P0441. Thinking if there is a vac leak, that would result in lean exhaust, which the O2 sensor would report to the PCM. PCM then would attempt to order up more fuel from injection, which would then result in rich-smelling exhaust?
I told him to check over the vapor canister, the entire length of the vapor lines, including line connections to canister, the purge valve, and the fuel tank, as well as the seal of the gas cap.
If no cracks or apparent leaks, would you suspect the purge valve/solenoid? Can it be tested with a vacuum source? (He is near my home in TX, and I have a hand-operated vac pump there).
Also told him about potential distributor issue with bearings. He said his truck is right at 170K miles, so that sounds like a real possibility. I suggested he put an ohm meter on his plug wires. He has replaced plugs and dist cap.

As always, I really appreciate you guys and A/F for the help.

even if the distributor looks good if he plans on keeping this vehicle it would be best to replace. many have had these issues. the converters do get damaged with this failure. vacuum leak would trick the O2 to cause the PCM to command longer injector on time sine it would report a lean condition...

[Ol'Jim]

I made a trip home, and this same truck had died on my brother in-law. Friday afternoon, I went to retrieve it with my son. Started up fine, sounded great, but after about 1 mile, it started "chugging" as if 1-2 cyls had stopped firing. Pulled into a parking lot. 1/2 hour later, it started, and sounded good again. got out on the road, and it did the same thing, but started losing power, along with the misfire. within 1/2 mile, I had to downshift to 2nd, then low, to keep moving while I looked for someplace to turn off the road. Would barely move the truck. Throttle setting didn't seem to affect it. Felt like fuel starvation to me. Went and got a tow strap, pulled it back to the house early Sat morning. Would not start, just an occasional firing, as in bad fuel pump. Did backfire through the throttle body once. Could hear fuel pump when key turned on. Put fuel pressure test gauge on it, and looked good, hit 60 PSI rather quickly. Maintained pressure while cranking. Told him about the distributor issues, so he bought a brand new one. Installed it, with no change in results. Double-checked wires & connections, everything seems to be in order. While cranking, it tries to start, firing erratically. You can smell fuel in the exhaust, and even see some black smoke from the tailpipe as it is trying to start. Checked for spark, it is sparking, though didn't look like a fat blue spark, but it was bright sunlight. Any suggestions on what to check next? Wondering about possible timing chain, but as I mentioned, it ran fine for a short while. Cleared code P0441, and now nothing comes up. Thanks in advance for any advice. -Jim.