Hi all,

I am presently having a problem with the emission control system on my '88.

Background: After tackling a plethora air intake component replacements during the summer months, I encountered a situation with the line that originates from the air pump, flows through a check valve then into the exhaust system of the engine. I believe this set up is for adding additional air to the exhaust during a cold start up. Anyway, the check valve associated with the system had rotted away over time and I was determined to fix it. The original setup, after the air pump, was the check valve attached to a brass support, that continues to a pipe that leads to the exhaust. Since the original check valve was in deplorable condition and I couldn't take it off, I ended up cutting off the check valve and its support, leaving just a bare brass pipe originating from the exhaust. I had no luck finding a machined piece that would fit the new check valve so I made do with a piece of plumbers PVC fitting in the shape of an "L". In order to make the check valve fit, I hollowed out the threads then used the threads of the check valve to make its own attachment. The other end of the PVC fitting was attached to the brass pipe via a rubber hose, clamped down with a ring clamp both ends. It worked for a while but ended up blowing off. I was told by a mechanic that I should just plug the hose originating from the exhaust and be done with it. I ended up doing just that.

The problem I was having in conjunction with this was with the TPS and control of the idle. An excellent suggestion from here indicated that I adjust the TPS manually to solve my idle problems and it worked like a champ. The issue I had after all of this was poor performance. My car felt like it was holding back, especially on steep hills. I also started getting heavy pinging from the injectors on excessive acceleration. I added higher octane to the mixture which helped a little. Anyway, as I was traveling today, I was pushing on the accelerator for one of those big hills, when all of a sudden, I heard a pop and an audible hiss from beneath the hood. Apparently the plugged rubber hose that I did in place of the check valve blew. Surprisingly, I didn't get a Check Engine code like I did when check valve previously disconnected. In addition, I had better performance and less pinging on the hills.

So here's the dilemma and any suggestions would be great. Do I make some type of plug for the brass pipe connected to the exhaust (non rubber this time) and continue with the reduced performance or is there another suggestion? Apparently there's a lot of pressure coming from that pipe and If it was hooked up properly, the check valve would prevent exhaust from venting into the air pump, thus the check valve.