Catalytic converter glows p1345 code is only code present

chevrolet
3500

#1

I have a 98 chevy 3500 box truck. The issue with my truck is that the cat is glowing i dont know how to go about it since the cat is replaced already. I tried pulling up codes and the only code i get is a p1345 can anyone please help me.


#2

The DTC P1345 indicates a problem with either the crankshaft or camshaft sensor circuit.

Since the engine runs, it’s not the crankshaft sensor circuit.

But camshaft sensor controls the ignition/fuel injection timing which can cause the engine too run rich.

And from the color of that converter, that’s going to be replaced.

Tester


#3

Ok so imma try that tomorrow morning and swap the cam sensor hoping thats gonna change the problem because i honestly dont know what else it can be. I tho it would be the rail or injectors or maybe even the o2 sensors but i do not get a code for any of that.


#4

That kind of code can come up if you did some repairs, and something went wrong

Was any kind of work performed recently . . . ?!

Besides that catalytic converter you already mentioned

Did you have the distributor out . . . ?!

I’m assuming you have the 5.7 liter gasoline V8, unless I hear otherwise, because that is the most common engine for your particular configuration and model year


#5

If a catalyst is glowing like that the engine has to be running so poorly that the cause should be easily found by a mechanic with a basic set of diagnostic tools.

I would drive the truck to the repair shop and no further. You already may be buying another catalyst.


#6

On a side note. All you people out there who like to remove broken heat shields instead of repair/ replace them. Would you like anything this hot right under your floorboard with carpeting?. Just saying.


#7

My guess: camshaft sensor failure or cam out of sync causing severe retard of ignition timing.


#8

There’s still an air gap between the cat and the underside of the floor. It probably wouldn’t be a big deal, especially since this is not a condition I would allow to continue.


#9

I indeed do have the 5.7 gasoline v8 and the truck feels like it has a crazy misfire but no code to one. Just that p1345.


#10

Any chech ignition timing???


#11

The code is pointing to the most likely suspect.
However, I had a similar problem and it was the coolant temperature sensor. No codes, just dumping in too much fuel thinking it was cold. Almost burned the truck down, the carpet was starting to smoke…


#12

Man guys i have to say thank you so much for all of your help to be honest! I checked out the truck opened up the center console( idk the right name for it), but it covers the engine which you can access from inside the truck. To my surprise there was three spark plug wires burned off. Ig whoever did the spark plug wire job didnt put em on the clips. Also i removed the cam sensor and looked under it and had small tiny holes so i replaced that just to be on the safe side. Now the truck is running like the champ it is! I erased the code and drive it for a decent length, stopped checked for any glow on the converter and nothing, theres no glow i can easily reach like 70mph on the highway when before i couldnt even reach 50 cause it felt like this engine was gonna blow the truck has 90k original miles, so i kinda canceled out the assumptions of burned internal engine part. I cant show the grattitude i have for you guys on here. Tou guys are the best! I will keep yall in prayer man this world needs more pol like you guys!


#13

You are correct. Over the years, hundreds, perhaps thousands of people have found help on their car problems on this board. Glad you were one of them.


#14

Wow i have terrible news this is just my luck. :disappointed: 4hrs after the problem was fixed for the glowing catalytic converter, the code p1345 re appeared both sensors have now been placed but the code remains there.


#15

I’m really beginning to think either your cam timing is off . . .

Or somebody had that distributor out, put it in wrong, your cam sync is now too far out of spec, and that’s the reason you have the code

Or perhaps your distributor drive is messed up . . . worn, apple-cored, etc. . . . and that’s the reason for the code

If that distributor isn’t close enough to where it’s supposed to be, you’ll definitely get that code

If I happen to be correct about the distributor, do yourself a favor and buy a complete new assembly, because it will come with the distributor drive gear AND a new cam sensor. You can even get ones that come with a new cap and rotor,


#16

I’m sorry to hear that.

Okay, you need to determine if something mechanical is causing the code.

A stretched timing chain can cause this code.

Remove the distributor cap. And while the rotor is being observed, with a breaker bar and socket on the crankshaft bolt, rotate the engine by hand in the normal direction. Now rotate the engine in the opposite direction.

If the engine can be rotated more than a few degrees in the opposite direction before the rotor in the distributor begins to rotate, the timing chain is stretched.

Worn/damaged distributor/camshaft gears.

Remove the distributor and check the gear for wear and burrs.

With a flashlight, look for any damage to the camshaft gear.

Tester


#17

Might try some basic tests,like intake manifold vacuum, ignition timing at idle that how it advances w/rpm. I’d probably also trace out the spark plug wires one by one, measuring the resistance end to end, to make sure they are all in good shape. If this is the type of configuration where there’s a replaceable distributor cap & rotor, replace those if there’s any sign of wear or carbon tracks. I’d probably also look under the hood at dark, see if there’s any sparks flying around. Spraying a little water with one of those plant misters can help make the sparks more apparent.


#18

That code has NOTHING to do with manifold vacuum, bad plug wires, etc


#19

Guys i have question for this same truck chevy 3500 Box truck. Just today i tried going in reverse and my truck wouldnt move. The truck has 94k miles how should i approach this issue. Any help will be appreciated. Ive noticed some spill around the differential, not sure if its differential fluid. Also the trans fluid looks kinda black but its full. Another thing is that theres some noise coming from the trans too. Its not a grinding noise, sounds like when you try to go in reverse at a highspeed but it does it in reverse or drive


#20

Just curious, did you ever resolve the code and glowing cat problem?

It works ok going forward, but when you shift into reverse it seems to shift ok, but it won’t move? What type of transmission does your truck use, automatic or manual?