First Porsche- 00 986 manual

[BoxsterRook]

Hi everyone,

Just got my first Porsche back on June 1: Meridian Metallic 00 986 manual, had just over 84k miles on it when I bought it. I'm up to 85.5k miles now.

I took it for a post-purchase inspection back in early June and had a few things fixed- spark plugs and tube seals replaced, new rear tires, new water pump. I also had a CEL pop up on my way to get it inspected- P1119. Mechanics replaced the pre-cat O2 sensor on 4-6.

Last month the horn started getting very sensitive, and then started going off during initial acceleration and braking. I DIYed it- siliconed the grommets on the bracket and have had no issues since. Couldn't find #31 O rings here in the desert, or would have done that. I attribute most of this sudden onset of soft tissue failure to the extreme dry heat here (I live in NV). I got the car in CA.

Today I got a P0430. Did some research on here and Rennlist, and looks like people have attributed this code and my previous code to any of the following:

MAF dirty or failing - cleaned or replaced
Fuel Pressure Regulator failing - replaced
Pre-cat O2 sensor heating element failing - replaced O2 sensor
3-way cat low conversion rate/ CAT failing- replace CAT
I have the stock exhaust system, so not including issues arising from aftermarket exhaust

My synthesis of the collective wisdom of the 986 fora is that 1. OBD II codes are a symptom, not necessarily the cause and 2. you need a coordinated diagnostic plan to figure out what's really wrong. 3. It's usually not the CAT, since they are designed to last 8 yrs/80k miles.

If anyone is willing to look at my plan and give me some feedback, I'd be very grateful:

1. Swap the downstream O2 sensors and see if the code switches to the other bank
2. Clean the MAF, or replace it
3. Check for leaks in the exhaust system
4. Figure out how to tell if the CAT is actually bad, test it, replace if necessary
5. Check the fuel pressure regulator

The fact that I got these codes in close tandem on the same bank seems like an important clue. I'm in the midst of moving back to SOCAL right now and don't really have time in the next week to do good research. I did find one thread that wasn't terribly helpful in terms of understanding the connection between the two codes.

Also if anyone could recommend a SOCAL Porsche mechanic that they trust, I suppose I should have one for last resort. It sounds like Sunset is the go-to parts place.

Thanks and I'm excited to be part of this community!

[Luccia at Pelican Parts]

Welcome to 986 forum! This is more of an introduction section so please head over to the Boxster Discussion forum and post your question/issue up in there. Many of our community members should have input for you. BBi Autosport is in SoCal and are great at what they do. Maybe check them out. We also supply parts. Also, be sure to check out our tech articles while you continue to diagnose the issue. Post a picture for us here when you can.

Porsche Boxster 986/987 (1997-2004) Technical Articles | Pelican Parts
http://www.pelicanparts.com/Porsche/index-SC.htm

[JFP in PA]

Originally Posted by BoxsterRook

Hi everyone,

Just got my first Porsche back on June 1: Meridian Metallic 00 986 manual, had just over 84k miles on it when I bought it. I'm up to 85.5k miles now.

I took it for a post-purchase inspection back in early June and had a few things fixed- spark plugs and tube seals replaced, new rear tires, new water pump. I also had a CEL pop up on my way to get it inspected- P1119. Mechanics replaced the pre-cat O2 sensor on 4-6.

Last month the horn started getting very sensitive, and then started going off during initial acceleration and braking. I DIYed it- siliconed the grommets on the bracket and have had no issues since. Couldn't find #31 O rings here in the desert, or would have done that. I attribute most of this sudden onset of soft tissue failure to the extreme dry heat here (I live in NV). I got the car in CA.

Today I got a P0430. Did some research on here and Rennlist, and looks like people have attributed this code and my previous code to any of the following:

MAF dirty or failing - cleaned or replaced
Fuel Pressure Regulator failing - replaced
Pre-cat O2 sensor heating element failing - replaced O2 sensor
3-way cat low conversion rate/ CAT failing- replace CAT
I have the stock exhaust system, so not including issues arising from aftermarket exhaust

My synthesis of the collective wisdom of the 986 fora is that 1. OBD II codes are a symptom, not necessarily the cause and 2. you need a coordinated diagnostic plan to figure out what's really wrong. 3. It's usually not the CAT, since they are designed to last 8 yrs/80k miles.

If anyone is willing to look at my plan and give me some feedback, I'd be very grateful:

1. Swap the downstream O2 sensors and see if the code switches to the other bank
2. Clean the MAF, or replace it
3. Check for leaks in the exhaust system
4. Figure out how to tell if the CAT is actually bad, test it, replace if necessary
5. Check the fuel pressure regulator

The fact that I got these codes in close tandem on the same bank seems like an important clue. I'm in the midst of moving back to SOCAL right now and don't really have time in the next week to do good research. I did find one thread that wasn't terribly helpful in terms of understanding the connection between the two codes.

Also if anyone could recommend a SOCAL Porsche mechanic that they trust, I suppose I should have one for last resort. It sounds like Sunset is the go-to parts place.

Thanks and I'm excited to be part of this community!

P0430 is for low conversion rates on the three way cat on bank 4-6. typically means you need a new cat. The rest of the suggestions are off base. You need to scan the car with a Porsche specific scan tool, watching the before and after cat voltages.