Threw code P1155. Probably from removing cats?
Threw code P1155. Probably from removing cats?
No longer have the cats on my car and after about 50 miles, with the O2 foulers, got a P1155.
Sound about right?
Sound about right?
Last edited by BauerR; Feb 27, 2016 at 10:57 AM.
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From: Benton County, AR
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P1155 - O2 sensor ahead of cat. conv. Cylinder (4-6) exceeds limit value.
The error points to the #1 sensor, not the #2 sensor and this suggests an intake air leak and not necessarily a sensor problem.
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Pre-primary O2 sensor exhaust leak on the passenger side. I just spent months trying to figure out that code. A few turns of the exhaust nuts on the turbo fixed the problem. The leak is either letting outside air in or letting exhaust out, both of which can throw off the o2 reading.
It could also be a failing primary O2, but I'd check for leaks first. I changed my O2 first but it didn't fix the code. I also didn't have any visible signs of an exhaust leak, but the exhaust nuts definitely weren't as tight as they should have been when I finally tried tightening them.
It could also be a failing primary O2, but I'd check for leaks first. I changed my O2 first but it didn't fix the code. I also didn't have any visible signs of an exhaust leak, but the exhaust nuts definitely weren't as tight as they should have been when I finally tried tightening them.
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did you replace the Oring gasket? they are one time use. they crush when tightened so reusing them will allow for leaks
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Joined: Jun 2009
Posts: 2,190
From: Benton County, AR
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Second this. Every time my 996 Turbo has been in and the exhaust system has been removed the tech always replaces these metal o-rings that seal the turbo to the exhaust.
+1...have also dealt with this before.....exhaust leak at the turbo-exhaust interface...new orings and check/file the exhaust flange for flatness
Your o2 spacer/fouler may also be to blame
Your o2 spacer/fouler may also be to blame
Pre-primary O2 sensor exhaust leak on the passenger side. I just spent months trying to figure out that code. A few turns of the exhaust nuts on the turbo fixed the problem. The leak is either letting outside air in or letting exhaust out, both of which can throw off the o2 reading.
It could also be a failing primary O2, but I'd check for leaks first. I changed my O2 first but it didn't fix the code. I also didn't have any visible signs of an exhaust leak, but the exhaust nuts definitely weren't as tight as they should have been when I finally tried tightening them.
It could also be a failing primary O2, but I'd check for leaks first. I changed my O2 first but it didn't fix the code. I also didn't have any visible signs of an exhaust leak, but the exhaust nuts definitely weren't as tight as they should have been when I finally tried tightening them.
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