DTC 301 code

[Woodie83]

EGR would not cause a misfire code, especially one for only one cylinder. EGR feeds into the intake manifold at the throttle body, how would it effect a single cylinder?

There are specific codes for EGR, the engine turns it on at a steady state cruise and watches the MAP sensor to see the change in intake manifold pressure. If stuck on, your engine would barely run, if stuck off it would run fine but an EGR code would be displayed.

[syrjr1]

The factory service manual says that a malfunctioning EGR can cause this code. It also cites several other conditions, besides the obvious plugs, wires, cap, rotor and coil, as possible causes of this code.

[Woodie83]

Good luck with it, I'm done. Everything that has been suggested has been totally rejected by you as a possibility, why ask a question and then not even consider the answers you get?

[syrjr1]

Rejected??? I already checked out all the possibilities all of you have suggested before I started this thread. The suggestions were not rejected. I found no abnormalities other than the corrosion on the distributor cap center post. I am an accomplished mechanic and have never had a problem finding and fixing situations like this. This one has me though. It is very frustrating. I'm going to replace the EGR solenoid this weekend. If that does not work then i'll know one more thing that is not the problem. I do appreciate all the input you all have given.

[Woodie83]

Maybe you're not communicating that very well, or maybe I'm just a grumpy old coot. In retrospect, the second possibility is the most likely.

Sorry

[Johnny Mullet]

I still suspect a burnt valve.

[syrjr1]

Well folks I replaced the EGR vacuum solenoid with a junk yard replacement. There was no change. Evidently the blow test in the manual is wrong. I also picked up a PCM out of a 98 or 2000 (not sure of the year) 1.0 and tried it. Not only did I get the 301 code but also got a 1401 code. Most likely the junk yard PCM is not compatible with the 97 sensor. I put the original PCM back in this morning. I also did another compression check followed up with adding oil and a second compression check. There was no difference between test 1 and 2. There is no compression problem as I stated earlier. No burnt valve and no broken valve springs. When I removed the plugs for the compression test and inspected them I found something. The plugs for cyl #2 and #3 are the usual coffee w/cream color. #1 plug looks like coffee w/alot of cream. Not white but slightly colored. These plugs have less than 200 miles on them so i'm not sure if I have a problem. The lighter #1 plug suggest to me that there may possibly be a slight intake leak. I'll have to check for a leak w/starting fluid. This problem has really kicked my butt.

[syrjr1]

Houston we've found the problem. Intake leak at the #1 cylinder/intake manifold gasket. Right at the outer most bolt. Using starting fluid to detect worked. Boy am I glad I found it. It is a very slight leak. Manifold vacuum at idle was within specs. Surprising that this leak would show up after 60,000 miles. I need to change the gasket to verify but this sounds promising. Wish me luck.

[syrjr1]

The intake gasket was split about 1/8" causing the leak. I should have figured this out earlier since it only involved the #1 cylinder but was looking for the obvious problems thinking that a vacuum leak would only be in a hose. I must be getting old... I needed a tuneup and needed to change the coolant anyway. I'll put it back together tomorrow and verify. Thanks to everyone who provided input on this thread.

Ron

[syrjr1]

I put the intake back on this morning with a new gasket. Problem solved.

Ron