99 poor idle
Thread Starter
Drifting
Joined: Aug 2009
Posts: 1,346
Likes: 160
From: new iberia la
99 poor idle
My wifes 99 with 100K on it, started exhibiting very poor idle at redlights in gear.. I scanned for codes and only 1 downstream 02 sensor came up.. That's not enough to produce the very bad idle ,stumble and even stalling.. well, after some investigation, I found the source of the problem.. the PCV hose had a 1/4-3/8 inch hole in it.. not anywhere near heat source.. it looks as if oil settled in that spot and eventually degraded the rubber hose.. its very thin in that area..replaced it, runs perfectly again. just a heads up ,if any of you experience similar conditions.
Drifting
Joined: Mar 2013
Posts: 1,496
Likes: 355
From: Little Rock Arkansas
Pre-2001 LS1s are well documented to have PCV issues. A good amount of the issues were revised 2001 onwards with the introduction of the LS6 intake and revised PCV setup. It's a very good idea to service the PCV setup yearly (yes, at the least yearly on a well-driven C5) if you have a pre-2001 C5. The MAF and throttle body get easily gunked up and the whole system often exhibits the settling issue like you described.
Despite any arguments against the contrary and for sure people can argue the system works as engineers designed, a good catch can system on pre-2001 C5s can do wonders in helping with the PCV and gunking issues.
Despite any arguments against the contrary and for sure people can argue the system works as engineers designed, a good catch can system on pre-2001 C5s can do wonders in helping with the PCV and gunking issues.
