Falco21

First off, let me say hi to everyone! Been a member on 2 GTO boards, decided to join here. Have heard great things about this place! Here is my problem:

About a week ago, we were hit with a massive storm. Tons of rain and flooding. Well, unfortunately, I was leaving class when this happen, therefore I was stuck in the middle of it all. Had to go through some pretty deep water, but nothing very deep. About 10 minutes from my home, the car started to run terrible. There was a distinct smell of gas in the car and the MPG dropped to no higher than 7. I usually average around 15. Also, the car started to run rough and idle rough. When crusining, the car would also buck back and forth.

I was able to limp it home and had the codes read. It showed up as:

P0171 - Bank 1 Lean
P0174 - Bank 2 Lean
P0175 - Bank 2 Rich
P0300 - Random/Multiple Misfire

I pulled all the plugs and they were all caked black. Had all new plugs installed, had new plug wires installed, and cleaned the MAF sensor. I also ordered new 02 sensors and had those installed as well. Started her up and the problem continues on. I started searching for a Vacuum Leak and found nothing. The MAF looks fine, but I did find that the Evap Purge Solenoid was broken. Could this be causing the issues I am having? Any ideas would help a ton!!

Here is the broken piece:

Falco21

Anyone have any ideas?

Darkman

iTrader: (2)

Based on your facts, my first guess would be water intrusion into the O2 sensor connectors/wiring.

Also, broken EVAP components is a listed item on the GM troubleshooting chart for the P0174.

Falco21

That's what I originally thought. I replaced both 02's and still the problem persists.

Darkman

iTrader: (2)

Water intrusion problems often cure themselves once everything (like the connectors) dries out. Have you replaced the EVAP part yet?

Falco21

I used epoxy and put it back together. Looks perfect again.

I have not been able to install it yet, because it has rained over 3 inches today. The sun has not come out once all day. It's so frustrating trying to deal with this water damage and it just keeps raining non stop every day.

Robofuzz

A massive vacuum leak can give you those codes, I believe. So hopefully fixing that part will fix your issues.

bnvus

OP any word?

Falco21

I fixed the part with epoxy and re-installed it. Everything seems to be working fine. I cleared the codes and no code has popped up after driving with it all day today. Car seems to be running fine as well.

The only thing is, I need to take a look at the plugs again. I had put in new plugs and wires thinking that was the issue, but it was not. I have not pulled the plugs again after testing it that second time, so the plugs could be caked again. I gotta check them out tomorrow.

Jontall

You could always thread-in a brass nipple if the epoxy doesn't hold.

Falco21

Well, I changed the plugs and they all had a slightly white tint on the tips. As stated in the first post, the car was running both rich and lean, so I think by replacing the 02 sensors, it fixed the rich portion, but the vacuum leak was causing it to run lean, thus fouling the plugs. Now everything is replaced and back in. Car runs perfect

Nytehawk

My first guess would have been O2 death by drowning, temperamental little things.

Glad it worked out for you, OP, from one GTO owner to another. How did you find that vacuum leak? seems so random, and yet causing all sorts of hell.