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CATALYTIC CONVERTER HOW WOULD I KNOW IF IT NEEDS TO BE REPLACED PLEASE HELP!!


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GRINERGURL
User

Oct 22, 2014, 4:44 PM

Post #1 of 9 (2385 views)
CATALYTIC CONVERTER HOW WOULD I KNOW IF IT NEEDS TO BE REPLACED PLEASE HELP!! Sign In

I JUST GOT A CHEVY SILVERADO 2500 VORTEC ENGINE SIZE 3500 WHEN IM DRIVING AND PICK UP SPEED IT BACK FIRES WHEN I PUT IT IN PARK AND PRESS THE GAS IT BACK FIRES DOES ANYONE WHAT CAUSES THAT SOMEONE SAID IT COULD BE THE CATALYTIC CONVERTER WELL THERE IS TWO ON THIS TRUCK DUEL EXHAUST PIPES ONE SIDE BLOWS OUT CLEAR SMOKE THE OTHER SIDE KIND OF DARK ALSO WHEN IM DRIVING IT CUTS OFF BUT IT DOES START RIGHT BACK UP CAN ANYONE TELL ME WHATS GOING ON WITH THIS TRUCK


(This post was edited by GRINERGURL on Oct 22, 2014, 5:36 PM)


Tom Greenleaf
Ultimate Carjunky / Moderator
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Oct 22, 2014, 5:07 PM

Post #2 of 9 (2373 views)
Re: MY CHEVY 2500 VORTEC BACKFIRES I NEED HELP Sign In

Can you start over and unlock your caps key and say what year this thing is with what engine please and include miles on this too.


Backfires are not the first thing I would think of for a clogged catalytic converter,


T



GRINERGURL
User

Oct 22, 2014, 5:23 PM

Post #3 of 9 (2368 views)
Re: MY CHEVY 2500 VORTEC BACKFIRES I NEED HELP Sign In

Its a chevy 2500 Silverado Vortec LS The engine size is 3500


Tom Greenleaf
Ultimate Carjunky / Moderator
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Oct 22, 2014, 5:48 PM

Post #4 of 9 (2355 views)
Re: MY CHEVY 2500 VORTEC BACKFIRES I NEED HELP Sign In

Right now all we know is this thing backfires and likely a 3/4 ton truck with Silverado trim. 3500 is either a 1 ton or what for an engine and no year listed but doesn't matter much.


No dual exhaust known from new just dual tail pipes to me so that must be custom work.


Back fires are usually either spark gone wild or valve timing not common on Vortecs to me. Any messing with the distributor would be a problem.


In order to help you, you need to say what the heck this thing is for a beginning. Anything recently done to it would help too,


T



Discretesignals
Ultimate Carjunky / Moderator
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Oct 23, 2014, 4:35 AM

Post #5 of 9 (2320 views)
Re: CATALYTIC CONVERTER HOW WOULD I KNOW IF IT NEEDS TO BE REPLACED PLEASE HELP!! Sign In

What is the VIN number?

If the check engine light is on, have it scanned and write down the codes.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Oct 23, 2014, 4:36 AM)


kev2
Veteran
kev2 profile image

Oct 23, 2014, 8:02 AM

Post #6 of 9 (2310 views)
Re: CATALYTIC CONVERTER HOW WOULD I KNOW IF IT NEEDS TO BE REPLACED PLEASE HELP!! Sign In

You just acquired this vehicle - have it scanned for codes anyway.... All to often I have seen sellers disable the CEL.

THe request for the vin is to help identify the powertrain - engine size etc....


GRINERGURL
User

Oct 24, 2014, 1:31 PM

Post #7 of 9 (2286 views)
Re: CATALYTIC CONVERTER HOW WOULD I KNOW IF IT NEEDS TO BE REPLACED PLEASE HELP!! Sign In

YOU HAVE BEEN VERY HELPFUL I MADE A MISTAKE ITS A 350 SIZE ENGINE


Tom Greenleaf
Ultimate Carjunky / Moderator
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Oct 24, 2014, 1:59 PM

Post #8 of 9 (2281 views)
Re: CATALYTIC CONVERTER HOW WOULD I KNOW IF IT NEEDS TO BE REPLACED PLEASE HELP!! Sign In

"Vortec" and 350 is in C.I.D = a 5.7. 8th digit of VIN would be an "R" and this wants proper fuel pressure way up there as some go or will not run well or at all.


Now subject line asks how you know if a converter is good or not. This (do we know the model year yet?) should have before and after O2 sensors both sides in exhaust. Before converter ones can change how it runs and ones after tell how well it did or if ever run poorly for too long will not give proper readings and any can and will throw a code and pinpoint which one has a fault.


Always time for one but never seen one clog up yet on these but could not operate as a converter well or clog would set code and loss of power as an exhaust restriction would. That can be measured either by intake manifold vacuum testing or back pressure testing. Are you up to either and have tools to do that? Vacuum gauge or pressure gauge on missing O2 sensor which will probably give you a total hard time to remove or break or worse hurt pipe it's threaded in to which is very costly if not fixable. Some will drill a hole but if you really suspect converter there are much better ways to tell,


T



Hammer Time
Ultimate Carjunky / Moderator
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Oct 24, 2014, 2:12 PM

Post #9 of 9 (2276 views)
Re: CATALYTIC CONVERTER HOW WOULD I KNOW IF IT NEEDS TO BE REPLACED PLEASE HELP!! Sign In

I've seen 2 requests for codes and no response yet.



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