Running too rich: codes 1130,1128,1124

[R0gerB]

I have a 2001 Boxster 2.7L tiptronic with 139,000 miles. Daily commute driver. Mods are intake with cone filter (non oiled filter), headers, full exhaust with no cats. I needed to get the car inspected so I put my factory headers back on with the cats built into them and have been having a world of problems ever since. Also i should note that i used the same intake gaskets for the headers, so with my factory headers currently installed, it does have an exhaust leak although it is not a huge leak.

The car was running very rich and had a rough idle. I checked the codes and had the 1130,1128,1124 codes, all being 02 sensors rich threshold. From what i understand, this does not mean that the sesors are bad. After researching on this site for similar problems, i suspected a vacuum leak. I first removed the oil cap while the motor was running and there was a little suction on the fill tube, which the engine tried to compensate for when the cap was removed. I then took off the intake to check all the vacuum lines, the intake had small pools of oil in the tubes, more than just a mist, so i went ahead and replaced the AOS along with a cracked "J" tube from the seperator to the intake. All the vacuum lines looked fine and i could not find any leaks. I cleaned the MAF and put it back in and it did not seem to change anything, although at cold start after cleaning with MAF cleaner it would run for a few seconds and then the motor would die sometimes. When the engine is warm it will stay running though with just a rough idle. I disconnected the battery for 10 minutes, unplugged the MAF, and started the car...this time the engine did not die but it still had a rough idle.

I am not sure what my next step should be...should i go ahead and fork over the money for a new MAF or is there anything else i can possibly check first? running rich am i safe in assuming that my fuel filter and pump are fine? any tips or advice would be greatly appreciated, thanks!!!

[infocusf8]

I had those same codes and although my '99 Boxster was running rich it was not idling hard. It took three smoke tests to find that the small bellows hose from the secondary air vacuum tank had a pinhole leak in it and a vacuum line from the secondary air diaphragm under the intake manifold had become disconnected. When you start your car up first thing is the secondary air pump working? It should run and sound like a vacuum cleaner for a while until the car reaches operating temp.

[R0gerB]

Thanks for the tip! man, i just started the car up for about 15 seconds or so...that air pump did NOT come on. I am assuming it is supposed to turn on right as soon as the vehicle is started? i removed the pump and tested it with 12 volts and it turned right on so at least i know it works...what sensor or valve tells the air pump to kick on...maybe thats my problem?

[R0gerB]

My ABS light comes on after driving a few minutes, after doing more research i know there are some vacuum lines associated with the system...is it possible that i do have a leak somewhere causeing the ABS light to be on and the Air Injection Pump to not come on?

[infocusf8]

My ABS light comes on after driving a few minutes, after doing more research i know there are some vacuum lines associated with the system...is it possible that i do have a leak somewhere causeing the ABS light to be on and the Air Injection Pump to not come on?

More than likely you have a vacuum leak somewhere but you could also have a voltage problem or both. Your secondary air system is supposed to come on right away and if it doesn't then the entire system will need to be checked including voltage to the pump to see if the correct amount is being delivered. If you don't have a Bentley's Manual now may be a good time to purchase one as it will show you all the components of the secondary air system and what to check for. In my case it was the small rubber bellows from the vacuum tank and a hose from the diaphragm under the intake manifold (you have to remove the intake manifold to access it). There are one or two more diaphragms with vacuum lines in the system that could be malfunctioning. I found out after the system was repaired that that small rubber bellows is a common part to malfunction as it is a twenty cent part that costs a couple of hundred dollars to replace. If your ABS light is on there is a vacuum system associated with it in the front of the car behind the carpet on the driver's side. You might check there to see if a vacuum line is malfunctioning.

[R0gerB]

Well I replaced to MAF today. It really seemed to help the motor idle alot smoother, also the air injection pump comes on now. The weird thing, the car has an occasional missfire since replacing the MAF and it didnt before! Is this normall to have a miss after replacing a faulty MAF? any ideas?