Where to Start Fixing? P0170 with Multiple Suspected/Known Issues

[gyphonftw]

Hi all.

I'm picked up a stock 2g (99) GST spyder about 2 weeks ago. I have a P0170 code on and multiple known issues and 1 suspected. Now I'm a loss on where to start setting things to right.

Known Issues:
1. Small Exhaust leak (~1-2mm) in flex pipe.
2. 2nd leak cat attached with claps
3. Downstream O2 sensor reads flat 0v (Upstream cycles normally
4. Exhaust past downstream O2 is very rusty

Suspected issues:
5. Hissing sound near solenoid above turbo.

Questions on repairs:
1. Where to start?
2. Best place to introduce smoke to the vacuum system for leak check?
3. Can I patch the exhaust or do I need to replace the downpipe now?
4. Anything you think I should know.

Thanks for looking, hope you have an idea

 

[19jdmdsm91]

To check for vacuum leaks try a boost leak tester... super easy to make. If you have a smoke machine (expensive)... you can introduce the smoke from almost any hose. I like the blow off valve nipple. Or the brake booster after the one way valve...meaning straight to the manifold. Yes you can use special exhaust repair putty, clamps, cut off bad piece weld new one, etc. To me it sounds like you have a boost leak though. Good luck!