: P0301 #1 Cylinder Misfire 97 Catera

05-14-11, 03:36 PM
Ok, so i have the 98 catera back together. Engine light came on and the code read P0301, which is the #1 cylinder misfire. Checked the plug(Bran new) and swapped it with #3 plug. Still P301. Swapped #3 plug wire with #1 and still P301. That leads me to believe it is the coil pack....Is there anyway to test the coil pack before I up and buy a new one ??

05-14-11, 03:45 PM
My bad I know the post says 97 but its a 98 !! I know its not much of a difference.

05-14-11, 06:46 PM
Take the #1 plug out of the coil pack and smell the end of it if it smells like gas then its bad. I just replaced mine . If you go to my other thread PROBLEMS A-Z I gave a full description of how to replace coil pack.

05-14-11, 08:10 PM
So, just take the plug out of the #1 spot of the Coil Pack ? then smeel to ssee if the wire smells like gas ? if it does then the coil pack is bad ? Ok, I am thinking the coil pack is bad but this will help. Thank you.

The coil pack will be no problem. I just had the heads off to do a complete valve job. This is the only problem I have now. I also have some white goo build up at the top of the Oil Filler Tube.

I will check the Coil Pack and let you know.

05-14-11, 08:43 PM
Hey..I had the same PROBLEM...It turned out a bad #1 Intake Valve. I did ALL the same stuff you did. Save yourself the headache and pull the head! If you really want to test it for sure. Pull the #1 Plug, get an adapter to screw into the spark plug hole push compressed air and "Blow Back" through it. If you hear air (audible - shhhhhhhhhhhhhhhhh) coming out the Throttle body - (Manually open it), you have a bad Intake Valve. A compression test will get it too. The compression test on a good cylinder will read almost 200psi. Bad intake, about 35psi.

To test you are getting good spark from the coil pack, you can get a Spark Plug tester that actually shows them firing. I can almost bet you it is NOT the coil pak. Those things are heavy and the way they are built is rock solid.

Pull the head. When you are ready, let me know and I will save you a TON of hassle. I know all the short cuts and everything you need right down to the TINY seals in front of the Intake plenum! :-)

In regards to your private message to me:

Can you give me more info on the rubber "Valve" you were talking about. Is it where the 2 vaccum hoses plug into.

Oh yeah...you bet...it is a FLAPPER valve of sorts, about the size of a postage stamp. (And yes, there are 2 hoses coming from it that plug into the back of the intake plenum.) It is inserted in the PCV unit that is mounted to the block DIRECTLY behind the Passenger side head. Since I had my head out, I pulled it and was going to re-seal it, etc. MAN, I took it out and it was literally COVERED is "goo." (Picture a snot nose kid - literally!) :-)) I ran it through the washer and then is was clear what was going on. That rubber check valve had completely rotted and was brittle. When I touched it literally crumbled. The goo was the only thing holding it together.

So..I had to order a whole new PCV canister and it came with the new check valve in it. The goo problem is due to excess moisture in the oil. It is just about gone now after a full oil flush and numerous oil changes. I have also noticed my engined has smoothed out quite nicely.

If the passenger side head is pulled, yanking the PCV canister and checking it out is standard. You will actually want to just check the valve to make sure it is not rotting and that the rubber is firm. Otherwise, replace it. (Note - I saw you had the heads done...see my post below)

NOTE: Don't forget to check all the other stuff everyone neglects. On side note...my caddy is running great and the work I put in has been well worth it.

Next on the list is new control arm bushings and newly ultrasonically cleaned fuel injectors. I just paid 35 for a full set of injectors on eBay that had them PERFECTLY cleaned by Mr. Injector (Bill Johnson) out of Coeur d'Alene Idaho. $101.00 for a full clean, test, output report and seal replacement. Can't wait to drop those bad boys in.

Keep me posted how your Caddy work goes. I know this car quite well now and enjoy the hell out of it. We took it on a nice road trip a few weeks back - smooth as silk.

05-14-11, 08:49 PM
Okay..I just noticed you said you had the heads re-done. Okay DO THIS.
Perform the Compressed Air Test. If you hear the air coming out of the intake, then your guys did it wrong. How do I know? Cuz the clowns here did the same thing to me which is why I pulled the head MYSELF and did the work MYSELF! This car is hard to work on and unless you take it somewhere where they have pulled a Catera head, they will not do it right!

To REALLY prove this: (This is a little more in depth)
1) Pull the Intake Plenum.
2) Pull the intake manifold
This will expose the intake side of the head and you can actually SEE the valves. The number 1 cylinder is the Passenger side - FRONT, most forward intake hole.
3) Pour a little bit if tranny oil, or regular oil right in to the intake.
4 Push compressed air from the #1 Spark plug. If you see bubbles then the head was NOT DONE CORRECTLY.

How do I know all this? Cuz I feel your pain and have done all the same stuff you are going through. :-)

Keep me posted.

05-14-11, 11:29 PM
you said you had the heads off did yu do the work yourself. If so then im sure you know its done right. My guess would still be the coil pack. what symptoms is the car having. White goo could be more than just one problem. Is it just on the oil fill or on the dipstick.

05-14-11, 11:56 PM
I did not do the valve job myself. I did however take the heads off and take them to a machine shop that did both heads. Cleaned, milled and valve job.

I was worried about the "Milky Goo" being a head gasket not done properly. It is just on the Filler cap and the filler tube. It is not on the dipstick at all or in the oil.

I will grab a compression tester tomorrow and will find out for sure about the #1 Cylinder test.

05-15-11, 02:07 PM
goo could be bad oil cooler or head gasket. It also could just be condensation. Wipe all goo off run car for half hour, look at cap and filler if no goo probably just condensation. if goo is still there than it could be head gasket or oil cooler.

05-15-11, 04:19 PM
Ok, did compression test on #1 cylinder. Compression is good, pushed 180. Just like the other cylinders. So now I am leading towards the coil pack !!!

I wiped the Goo off a couple of times now. It is just on the oil filler neck top and cap. The goo is not on the dipstick or in the iol itself..Might just take the intake off and check the PCV valve.

09-25-11, 05:33 PM
hi ive got a 2001 catera with a misfire on cylinder 1. Can please tell me more about which side is number one. i know you already stated which but ive been reading about the omega and some of the location are confusing because of the european passenger side and usa.

09-26-11, 11:01 AM
hi ive got a 2001 catera with a misfire on cylinder 1. Can please tell me more about which side is number one. i know you already stated which but ive been reading about the omega and some of the location are confusing because of the european passenger side and usa.

if you look at the engine, one head will be farther forward than the other. the one that is further forward will be cylinder 1. i believe it's on the right side (passenger) on American cars. not sure about European, but i would think they were the same.

01-04-14, 04:57 PM
Hey Elbrown4183!
Have the problem with Cylinder #1 since I got the car. Its 2000. Engine was rebuilt. I got some fancy tool to see Misfire data, and it shows misfiring counting when engine is under 1500RPM. When higher, misfire stops. Car runs just fine, spark plug is clean on #1 cylinder, the only issues is higher RPM on idle, Rich Bank 1, way richer than bank 2 (On higher RPMs its about the same. When 700 RPM I can feel constant shaking like one cylinder doesnt work, its only in that range. Today I replaced Coil and New plugs. Also I have to say, engine was built on Saturn Block with one head from original motor, another one came with Saturn. Valves were done also. Engine did 30K miles now, nothing chanched in perfomance, and Compression is about 190 on all cylinders. Would it last so long if intake valve leaked from the beginning??? What do you think?

P.S. I though about differences in heads and compression ratios for saturn and Catera, but if so should It get 3 cylinders misfiring, not just #1 right?!

01-06-14, 06:01 AM
U need to flash your injectors. I did it on mine. Look up videos on YouTube. U can do pro flash at home if u have air compressor. Before that Try to swap injector 1 with 2 and see if misfire moved to cylinder 2