Help, Fixed Exhaust leak after 3 codes, failed emissions

Basically. I busted a exhaust leak on my passenger side exhaust flange and immediately threw 3 trouble codes. p1131 and p1151 on my 2003 Mustang GT. I can't remember the other code. Fixed the exhaust leak and the car sounds as good as ever. Reset computer and drove 75 miles with my know check engine light. Pulled in at emission center and after the guy did his thing. Check engine light came on and through the 2 codes listed above. Now I'm at a loss on whats the problem.

The ideas in my head are replace the o2 sensor, my other idea is a leaky cold air intake.

Noticeable driving conditions. Shaky idle and a exhaust smell (Keep in mind, the exhaust leak is fixed, different smell than exhaust fumes)

Common sense tells me since the codes didn't pop up until after the exhaust leak at the passenger side exhaust flange. The problem would be fixed after the leak was fixed, but I guess not.

Thanks in advance

Josh

OK, This is the best I cna describe the idleing.

For 2 years, the idle has been normal after TB/Plenum install and tune. My normal idle is 800 rpms. But the rpm's would stick sometimes due to me not being able to adjust tps voltage to a perfect setting. Which many people have but nothing crazy or annoying.

After the codes were thrown and the exhaust leak. The idle was jumpy, shaky, erratic, however you want to word. Jumpy from 900-1100. RPM's stick in between shifting gears now. When slowing down from speed to a stop the idle will stay at 1800-2100 rpm's until i come to a complete stop and than drop to the normal idle at 800. Idle at randon times drops to 400 or so like the car will die. This is the best I can explain about the idling issues.

I just bought a MAF cleaner spray specific for just MAF'S and I'm gonna clean the housing, air intake, etc.

Whats frustrating is evidentially you have to drive 75 total miles for the codes to actually pop up.

I fixed my cars exhaust leak, drove 75 total miles. No check engine light. Get to emissions center after I get out of the car and the guy gets back in it. The check engine light comes on and I have the 2 codes.

From my memory the 3rd code was p1130 but that now seems to be fixed.

Update. Hopefully somebody can chime in.

Replaced both upstream o2 sensors and pulled MAF and cleaned it with CRC MAF cleaner. Checked for any vacuum or intake leaks. Unhooked battery for 30 minutes. Codes were cleared. Let car idle for 15 minutes and than let car idle for 15 minutes with the air on. Just for a start with the driving cycle so I can do emissions Monday. But check engine light came on. Hooked up my SCT and both p1131 and p1151 codes were showing again. So I went ahead and cleared them again with the scan tool route rather than unplugging battery. So now I'm at a loss. My Cold Air Intake isn't 100% anymore. Kinda 2 points where it is a small leak,BUT the CAI has been like this for a year with no issues or codes being thrown.

Somebody help me out if they can or have any experience.

Car has 64,000 miles.
Replaced both front O2 sensors - $90
Cleaned Maf - $8 for cleaner
Failed emissions earlier in the week - $10
Fixed exhaust leak - 2 hours time invested, time getting lowered car up, trip to Lowes for Nuts to use and the fix.

midnightdriver said:

First, is it possible to fix you cold air intake, leaks worsen with time and that might be the issue.

Those codes are for lean bank 1 and bank 2. When you got the O2 sensors, you got ones for the front right?, because if I remember right the front and back have different part numbers and I believe they are side specific too. Double check right is on right and left is on left.

Check for vacuum leaks on your pvc system also could have a bad pvc valve. That is the tube that goes across the top of the engine, from the passenger side valve cover to the cold air intake.

Try jacking up the car again and also double check that the exhaust is all tight including the manifolds. Don't know why your system broke but it could have affect the manifolds/headers if you have them too.

Lastly, I know this is out there but have you check you fuel filter. I am taking a while guess but a clogged fuel filter of fuel injector might cause you to run lean.


Hope this gives you some direction and report back any progress please

Where is WMBURNS when you need him!!!

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Part numbers from the original o2 sensors are the same and yes I am certain I got upstream o2 sensors. Actually had to go to two advance autopart stores to get 2 total sensors. Part numbers for the new o2 sensors are correct. No left or right and not on the old ones either. The part number for the factory Ford o2 sensors are the same and no difference between the two.

Basically I bottomed out hard in a 7 day span twice and busted the passenger exhaust flange 1 of the 2 nuts loose. A few days later in a mild snow the driver side hit on the exhaust flange and knocked out both nuts. So basically when I got under the car. It was like I was running open headers.

The day I installed the O2 sensors I checked all connections on the exhaust again. There is not an exhaust leak at all on this car anymore. I was plagued with exhaust leaks for a while but its fixed. The cars exhaust sounds really really good. Exhaust leaks are easy to hear on this car with the setup I have.

The tube that goes across of engine from driver side valve cover to cold air intake was deleted like 2 years ago. The intake hole there was capped off with a rubber plug and the spot on the valve cover on the drivers side where the tube was. Has a mini breather on it.

Actually the fuel filter was replaced with a factory ford filter a few months back.

The Cold Air Intake could be ghetto rigged maybe to make sure the small leaks are sealed. I'm ordering a new one anyway.

Here is a list of things checked and replaced.

Exhaust leaks are fixed. Only 2 points. 100% now
Front (Upstream) O2 sensors replaced with correct part numbers installed and tight.
Cold Air Intake - Iffy, definately not 100% and has 2 small leaks (1 is fixed and 1 is not, but keep in mind these leaks which haven't gotten bigger have been like that for 9-12 months prior to the engine codes) New CAI is on order.
Fuel Filter - OK

PCV has not been checked or replaced
EGR has not been checked or replaced
Voltage on TPS is not perfect. I think perfect was .97 to .99 but Ford says something along the lines of .5 to 1 can't remember at all what it was cause this was 2 years ago. But within Ford recommended voltage range

As far as vacuum hoses. I've looked up and down and all over the place. Can't find anything loose, undone, cracked, etc etc.

I want to say these codes did not pop up until the passenger side exhaust flange busted its leak. It was the same day. Prior to that exhaust leak the Cold Air Intake had the 2 small leaks. Without any codes.

Hope this helps

Now should I look into ACT, Intake manifold, replacing EGR.

At WOT the car seems to be dead on 100% performance. Acts like a normal bolt on geared GT should feel.

I thought the codes were basically saying o2 sensors reading lean but compensating and putting the car into a "Just keep me running mode and running rich rich"

Gas Mileage around town dropped to 10 miles to a gallon. A full tank of gas with all in town red to red light driving would be around 160 miles and a all highway trip on a full tank would net me 200 miles total. So gas mileage was 10/12 which I can't say sounds lean to me.

I think I might have had a domino effect thing go on. But before I replaced these o2 sensors. My knowledge of cars told me. The extra air that the o2's were seeing with the exhaust leak being right in front of them is what threw the codes, well along with the leak. But now I don't know.

Should I be worried now about my mini Cats on the Pypes xpipe?

joshjwc9 said:

Where is the actual leak on the CAI? Any leaks are bad...letting in unmetered air will throw a lot of things off with the computer thinking it is running leaner, so it dumps in more fuel. Get that fixed 100% then get back to us.

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One is where the connection from the air intake to TB is and the other is before the MAF at the connection. The issue is a Plastic bendable plastic Roush TB to Maf Tube and the connections I have caved them in.

Josh

trinity_gt said:

I think you need to get under the car and carefully examine the front O2 sensor wiring. If you hit something hard enough to break the exhaust at the flanges there's a chance the wiring may have been damaged if it was caught between the pipe and the floorboard, for instance, or drawn-taut or pulled etc.

You may want to disconnect the battery, pull the PCM connector off and use a continuity tester or ohmmeter to check for continuity between the PCM connector pins and the O2 sensor connector pins. There may be a break in the wiring that's causing both sensors to appear basically dead to the PCM (P1131 and P1151.)

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How would I go about accessing that area of the wires. It was a pain to even get to the plugs on both sides to unplug the factory sensors from the harness. 1 is ran basically above the transmission. I can get to the wires where the plug together but thats as far as I can get. If the trannny wasn't there it would be easy.

Update -

After I made my last post. Waited on a few parts and did a little odds and ends to it.

1. Cleaned MAF with CRC Maf cleaner
2. Installed new Cold Air Intake, Got a JLT and took off the leaky Roush.
3. Pulled PCV tube from pcv to intake plenum and cleaned it. Found the fitting/Nipple that goes into the intake plenum was loose for some reason. Like easy to pull out with hand. Installed that back with RTV silicone. Fixed a crack in the L shaped rubber boot from that same pcv to plenum.
4. Read DTC's and cleared DTC's and unplugged battery for 30 minutes.
5. Car idles great, hanging idle is gone, exhaust sounds great. Everything I'm hoping is 100% now.
6. Unfortunately I think I blew a headlight fuse, since both headlights stopped working. My light on dash for Brights comes on when I try to turn headlights on. So I doubt I blew both headlight bulbs.

PS

Just checked fuses and can't find a blown fuse. Checked the 30A fuse under the hood and both left/right hand fuses under dash ? Anybody have any input. The high beam light on dash for the brights is on when I flip the headlight knob on. Its dark and tired from working on the car so haven't pulled the headlamps out. For a car that was maintained perfectly from the time i bought it new in nov 02 until now 64K miles later. I sure have a **** load of problems lately. Sucks like hell.

Josh

I'll know tomorrow after driving if I've fixed the problem. I think I did. 2 small leaks after MAF and 2 pcv leaks. Since the car is idling better than it has in 2 years and the exhaust sounds better than it did in 2 years. Sounds like I did fix the problem. Unfortunately I have a headlamp issue now. But really hoping none of this comes down to a wiring issue.

Tim2002GT said:

Just curious if you have had a chance to drive the car and if the codes popped up again.

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Car seems to be good to go. Haven't went through emissions yet because of lack of miles driven for the driving cycle to be complete. I'm about 98% sure the car is fixed and the codes won't pop up. Cause of the issue of the headlights I haven't been able to drive at night the last 4 days. Waiting on 9007 headlight connectors to come in that I next day aired before the weekend hit. My battery ground I added to the car 4 guage came loose after the optima battery moved. So it for some reason sparked and didn't blow the headlight fuse but just entirely melted both Left hand and Right hand side headlight connectors.

About 45 - 50 miles have been driven in total since the last fix involving pcv hose and new JLT air intake. I was thinking about running it through emissions today but going by this guide first link below.

Ford Motor Company Driving Cycle

I've gotten a not ready reading a few years ago when my car failed to go through the full driving cycle even though there were no prior dtc's or cleared dtc's. I didn't realize how much was involved in a Ford OBD2 driving cycle before the computer is finished. I think that link is good for everybody to have saved as a reference.

But in simplest terms. The main problem was the fitting from the passenger pcv hose that goes into the Accufab Plenum. The fitting had to be RTV'd/Glued in. And the L shaped rubber boot about 3 inches past the Plenum connection was cracked.

With how the car idled 2 years ago around the time of the TB/Plenum install, I always thought it was a TPS or IAC issue when it was just a small vacuum leak in a pcv hose.

You guys who have hanging idle issues after a TB/Plenum install besides TPS voltage and a IAC that might need replaced or cleaning. Carefully inspect those PCV's hose since they have a couple connections and bend. That fitting/nipple from Accufab for the PCV hose is junk. Should have threads for a screw in install not just a tight jam in type connection.

Question for any of you. Is there anyway for me to check to see if my car has fully gone through the driving cycle with the pcm, etc or even a way to check for pending codes? All I have is a SCT Xcal2.

Thanks
Josh

PS Thank you guys that helped me out in this thread. Me, some research, yall and a good amount of time on this car; Made this car run better than it ever has in 2 years. With 2 air intake leaks, 2 pcv vacuum leaks, hanging/rough idle, 2 horrible exhaust leaks, 2 ruined O2 sensors and a total of 5 different codes, lol