I have code 33 when I do the paper clip trick. What are my options? I think "EGR Control Pressure/Baro Sensor Circuit High" is what the code stands for. Is this for emissions only and can it be bypassed?

One thing I noticed awhile back was my vacuum pump was making a knocking sound but it went away about a year ago and has not come back. I'm thinking maybe the pump has something to do with the check engine light coming on.

I noticed that when the light is on I can step on the gas and when I let up it goes off for a little while then comes back.

Thanks,
Soupy

Check vacuum at idle and 2000rpm for 25" - EGR valve is vacuum operated

Welcome to the forum! :welcome:

As gmctd noted, the problem is probably related to the vacuum/EGR system. As I recall, that's really the only thing that was computer-controlled on those trucks. The vacuum pump may have gone out or it may be going out. There might be a vacuum leak of some sort as well, so look for any cracked, broken, or disconnected vacuum hoses.

You can actually eliminate the entire computer and emissions control system if you want, but that may not be a good idea. If your truck has to pass emissions testing you've got to have all that stuff functional.

Hope this helps! :)

Welcome to the forum! :welcome:

As gmctd noted, the problem is probably related to the vacuum/EGR system. As I recall, that's really the only thing that was computer-controlled on those trucks. The vacuum pump may have gone out or it may be going out. There might be a vacuum leak of some sort as well, so look for any cracked, broken, or disconnected vacuum hoses.

You can actually eliminate the entire computer and emissions control system if you want, but that may not be a good idea. If your truck has to pass emissions testing you've got to have all that stuff functional.

Hope this helps! :)

My truck is exempt from emissions test. Can you tell me more about disabling the whole system? Will my truck run better or worse without it? Is it simple to do like just discontent computer and plug some lines?

Sorry for all the questions and thanks for welcoming to the forum.

Well, as I recall the only things the computer system controlled on that were the EGR (Exhaust Gas Recirculation) and EPR (Exhaust Pressure Regulation)systems. In other words it really doesn't do anything important. The EGR and EPR are only active at idle. You probably won't notice the difference if they aren't functional. Personally, I think the easiest thing to do would be to simply remove the bulb from the service engine light and disconnect and plug the vacuum lines to the EGR and EPR valves. Then the EGR and EPR are nonfunctional and the check engine light is turned off. I don't think the computer on that runs anything else, but it might. Somebody who is more familiar with the late model computer systems could tell you better than I can. Don't try anything until somebody confirms that it doesn't do anything important... I'm not really familiar with the computer systems... I'd have to look at a shop manual and I don't have one available.

All that said, since the system is so simple (as I recall, anyway) it is probably very easy to fix. It is probably related to the vacuum system so it would most likely be very simple to fix...