Mechanics

CHEVROLET SUBURBAN ENGINE PROBLEM

2003 Chevrolet Suburban • 130,000 miles

My suburban, z71, vortex 5.3L engine, blew a catalitic converters. This was shortly after a puff of smoke, that dissapates quickly comes out of the exhaust, the converter goes, check engine light goes on, etc. AFter its fixed, a check engine (running lean) light goes on, and then goes back off.
Now, the puff of smoke just came out again, no check engine light, but the codes say that its running lean.
-Some people say it could be a pcv valve that would leak oil into the exhaust.
-Others say, it could be a cracked intake manifold, or the intake manifold gasket.
When I look at the intake manifold, it does appear to either have a portion pushed down that would be a stablizer on the passenger side of the manifold, but aside from that, can't really tell.
When the engine starts, generally all good, just a small amount of liquid exits and drops to the ground when its started.
--On a side note, I was confused on the starburst showing on the air conditioner, apparently when starburst is on, that means that the ac is off, I have not had it on most of the time, so the AC unit compressor was actually on, despite the fact that its pretty cold outside.
Any ideas on my mystery problem? I really hate to blow another cat converter again, particular if I'm going to travel a few hundred miles. Last time it went, I couldn't even power up a hill & it had to be towed.
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Chuck howard
October 16, 2012.



What codes is it to be specific? Check fuel pressure. And it may be an air leak in the exaust prior to converter. We need the code.

Hmac300
Oct 16, 2012.
Yes, there is an exhaust leak right now, because the mechanic didn't weld the piece together, he c-clamped it for right now, and has to get another clamp to stop the exhaust from leaking so that it runs more quiet. So, yes, that is confirmed for the exhaust leak before the converter.

I can get the codes later on today, as I have it written down at work. The codes originally said it was a "mass air flow" and either an o2 sensor or cat converter, and the mechanic fixed the cat converter. Does this provide info enough or do you need the actual codes, which can get later today at work?

Tiny
Chuck howard
Oct 16, 2012.
Also, thanks for your help, very much appreciated, you guys are great and what a nice cause giving back

Tiny
Chuck howard
Oct 16, 2012.
We need the actual codes and the ones that are current not the earlier ones.

Hmac300
Oct 16, 2012.
PO 171 and PO 174

Tiny
Chuck howard
Oct 16, 2012.
Those are lean fuel on both sides of engine, check your fuel pressure it should be 55-62 psi unless it is a vinZ then it shoudl be 48-52 psi. If fuel pressure is ok check for a vacuum leak.

Hmac300
Oct 16, 2012.