: 01 Catera getting P0300 code



retho78
12-03-10, 12:21 AM
Hi,

My in-laws car had a P0300 code come up (random misfire detected). Where do I start? Could it be the plugs, coil pack or oil leak going into the plugs?


Thanks.

waco-brian
12-03-10, 10:38 AM
is that the olny code? could be low on fuel,bad fuel, excessive vibration, bad drive belt for a/c

waco-brian
12-03-10, 10:41 AM
i just went thou my notes i got that code on my 98 and it was the 6 plug coil pack lil diferant than the 2000

retho78
12-03-10, 11:14 PM
That's the only code that showed up on my scanner. The car has new timing belt, water pump and serpentine belt. These were replaced early this year. I don't think there is any vibration, but will check and see what exactly is going on. I think it may be the valve coer gasket leaking oil and going into the plugs.

retho78
12-18-10, 12:24 PM
Just an update, the check engine light randomly comes on and goes off now. I didn't do anything, recently filled up some gas and then the light went off and so far it is staying like that....weird!

RippyPartsDept
12-18-10, 01:06 PM
How many miles? when were spark plugs last changed? (or were they ever changed?)
it's very possible that one of the ignition coil packs/modules is the cause here

retho78
12-18-10, 02:06 PM
The car has about 135K and the plugs were changed early last year. I'm think it could be the coil pack or the plug wires, because once I started it the other the day, the car had a slight shake and when I accelerate it, the car would run fine and then it was okay. So far it is running fine, but will keep an eye.

RippyPartsDept
12-18-10, 04:37 PM
the shake on acceleration is probably due to the misfire

and i don't think you have wires... just a coil over plug module on each cylinder head

retho78
12-19-10, 12:31 AM
okay, will keep an eye and maybe replace the coil pack. How much does a coil pack cost?

hgqguy
12-19-10, 09:49 AM
ignition coils are around $135

RippyPartsDept
12-19-10, 09:19 PM
90584337 for even cyls
90584336 for odd cyls

list prices aren't exactly the same but basically $158
i can sell them for $100
each, of course (and before shipping)

Cadi Cat
12-19-10, 09:30 PM
Go to advance Auto parts. They have them for $96/side. It's not a gm part but personally who cares. Works the same!

retho78
12-20-10, 11:29 PM
Thanks, and they have the coupon codes all the time which may drop the price even lower.

retho78
12-20-10, 11:34 PM
I just checked in advanceauto.com and with the coupon code I can get it for $76 each.

CaddyObsessed
12-24-10, 01:02 PM
Whenever I get this code, its because there is water in the sparkplug hole between the boot and the plug. It grounds out to the head giving you a random misfire. Sometimes I hose off the engine and forget to blow the water out of these areas.

retho78
12-24-10, 10:26 PM
okay, thanks...the check engine light has not come back for couple days now.

retho78
02-26-11, 09:33 AM
Just an update! After few months without any problem (didn't replace anything), the check engine light came on two weeks ago , scanned it and it showed cylinder 6 misfire (don't remember the code). Turned the check engine light off and drove it for another week without any problems, then the check engine light came on again yesterday after driving it for few minutes. This time the check engine light flashed for few seconds and the car slowed down, would not accelerate enough, could only drive it like 20 miles an hour and brought it back home. Could it be that the ignition coil pack is bad?


Thanks.

RippyPartsDept
02-26-11, 10:43 AM
Could it be that the ignition coil pack is bad?

Yes - i think so

retho78
02-26-11, 11:22 AM
okay, thanks...will check it out and let you know.

retho78
02-26-11, 09:08 PM
I was just looking online for the ignition coil and I see some brands selling two kinds (same side), one with a white connector end and one with a black connector end. Does anyone what the difference are for these coils? I know that the prices are different!!!


Thanks

retho78
03-20-11, 10:33 PM
Another update, had a misfire again....this time it was cylinder 4. Replaced the coil and plugs, so far everything is running smooth.


Thanks.

waco-brian
03-21-11, 06:07 AM
sweet

retho78
03-21-11, 05:56 PM
Thanks, I also got a great deal on the coil. I ordered it online from Advance auto parts and used coupon code, then picked it up from the store. The one I got was the BWD brand, and it is made by Bosch. It looks exactly like the orginal one in the car.

retho78
01-14-13, 08:27 PM
The car is having the random misfire issue again.

I replaced the passenger side coil with new plugs a month ago because it was running rough with the random misfire (same code P0300) and it ran well until yesterday it started to do the same thing. I scanned this evening and it showed the same code P0300. Also, one of the O2 sensor has been bad for a while and has the code for that. Could that be the problem for the misfire or could it be something else?

Thanks.

98Geldog
01-15-13, 12:38 AM
O2 can make the car run rich if its bad. What I did for the random misfire code was a fuel system flush and ironically it worked.

retho78
01-15-13, 05:37 PM
Could the O2 cause the misfire? The faulty O2 was bank 2 and the coil I changed last month was on the passenger side.

98Geldog
01-16-13, 12:04 AM
No it would not cause a mis it self but if its faulty it could cause the ECM to either run lean (not enough fuel) or rich ( to much fuel) which would cause a mis. I would just change bank 2 coil and o2 sensor and add seafoam and go from there

retho78
01-16-13, 05:23 PM
okay, thanks. The codes are P0300, P0161 and P0160. I search online and several folks had this same problem and ended up changing the ECM too. I think I can get an exchange on the coil since it was replaced last month and still under warranty.

Previously for the O2 we were only getting P0160 now getting the P0161.

Hope the ECM has not gone bad.

RippyPartsDept
01-16-13, 05:37 PM
less common for an ECM to go bad than a coil

retho78
01-16-13, 08:04 PM
Okay, thanks. I have ordered a new O2 sensor and will replace the coil and check the plugs too.

nethic
01-16-13, 08:48 PM
how hard is it to change the coil yourself.

and whats more important, pre cat o2 sensors or post cat o2 sensors and will pre cat o2 sensors work as post as well ? can't seem to find post cat o2 sensors for 1998 catera, only pre cat.
would 1999 catera post cat o2 sensors work?

RippyPartsDept
01-16-13, 09:09 PM
PM me your VIN and ill find the sensors for you.

RippyPartsDept
01-17-13, 09:00 AM
ok so using nethic's VIN I pulled up the O2 sensors.

pre-cat aka upstream sensors
#90540984
$243.40 - list price each
$152.13 - forum price each

post-cat aka downstream sensors
#90540985
$232.90 - list price each
$145.56 - forum price each

I have one of each in stock that can be sold at even cheaper prices.
PM me if you are interested (I will need your VIN just to double check and make sure).

retho78
01-17-13, 06:01 PM
how hard is it to change the coil yourself.

and whats more important, pre cat o2 sensors or post cat o2 sensors and will pre cat o2 sensors work as post as well ? can't seem to find post cat o2 sensors for 1998 catera, only pre cat.
would 1999 catera post cat o2 sensors work?

The coil for the 1998 is behind the driver's side valve cover area. I think it'll be easier to access if you have the wipers out and the black hard plastic cowl out of the way......thanks.

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I got the O2 sensor from rockauto.com.

car5car
01-17-13, 10:38 PM
MAF sensor can be bad. I am going to get one for my car.
Disconnect MAF sensor, if engine runs better, replace sensor.
Worst thing about them, there is no code. Sensor sends wrong signal, but it is withing range.

retho78
01-21-13, 07:57 PM
Just a quick update, I replaced the O2 sensor (bank 2 sensor 2), ignition coil and plugs on the passenger side yesterday. It ran smooth and then the check engine light came on today and it's running rough. I scanned the codes and it's showing random misfire, cylinder 2 and 6 and also showing bank 1 sensor 2 bad. It's very strange after replacing one side coil, plugs and sensor then other side craps out :bonkers:

I feel like the ECM is gone bad causing all this problems. Anyways, I'm going to disconnect the battery tonight and hook it back up tomorrow and see how it does, hopefully resets the system and runs fine.



Thanks.

RippyPartsDept
01-21-13, 09:16 PM
I wouldn't be surprised if its the ECM

retho78
01-21-13, 09:27 PM
Yeah...I think it's the ECM. I'll check tomorrow and let you know. If there a way to flash/reset the ECM and see if i'll work? If in case the ECM is bad and needs to be replaced what's the best way to go, get a used one and program it to the car or go with a brand new one?


Also, Rippy - any idea how much a valve cover cost on 1998 Catera? Please let me know....thanks

RippyPartsDept
01-21-13, 11:31 PM
The only way to know if it's the ECM in a situation like this (which is sort of common) is to try a new one. Kind of sux especially after you've sunk $$ into other parts.

RippyPartsDept
01-21-13, 11:34 PM
Send me a pm or email with your vin (or just post it here as a last resort if you came send it privately). I'll see what I can do.

retho78
01-21-13, 11:55 PM
I have PM'd you....thanks.

retho78
01-22-13, 06:15 PM
Just another update, hooked the battery back and drove the car around today and no CEL so far, but still a little rough. I may have to replace the driver's side plugs too and check how it does.

retho78
01-23-13, 03:32 PM
So far no CEL but running a little rough. Planning to change the plugs on driver's now and tgen go from there.

retho78
01-25-13, 01:42 AM
The CEL came on today and it didn't show any misfire codes but changed the plugs on the driver's side. The codes were for the O2 sensors bank 1 sensor 2 and also showing bank 2 sensor 2 (I just replaced this sensor earlier this week). My feeling it's the ECM and feel a little roughness on idle.


Thanks.

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For the ECM, what numbers do we have to match to find a replacement? I see so many numbers on the label plus the part #90566574.

RippyPartsDept
01-25-13, 01:00 PM
k your ECM is #9196386
I think that the price I PMd you earlier this week was wrong

the current list price for that ECM is $1,600 (!!!)

I could sell it for $960.18 (but I realize that is still a pretty outrageous sum)

that number or the original number (9117544) are the only two that will work if you're going to try a used ECM
it appears that your ECM is specific to 1998 so you will have to find one from another 1998 Catera

...

sorry for the bad news

retho78
01-26-13, 12:22 PM
The ECM I may need replacement is for the 2001 Catera. My 98 Catera is fine only have valve cover leaks.

So the price you pm'd might be right for 2001, not sure just let me know.

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Also, let me know the ECM part number for the 2001 Catera....thanks.

RippyPartsDept
01-26-13, 12:22 PM
Did you send me the VIN for the 2001?

retho78
01-26-13, 12:33 PM
No, the VIN # I send was for the 98 (for the valve covers).

I do not have the VIN # for the 2001 at the moment, since it's my in-laws car. I can probably get it by tomorrow but just let me know how much a ECM cost, just an approximate figure is fine.


Thanks.

RippyPartsDept
01-26-13, 12:35 PM
ah ok ... i got a bit confused ...

the '01 price i gave you via PM was probably correct
(of course we'd like to make sure using the VIN before we send you off looking for ECMs)

retho78
01-26-13, 12:40 PM
okay, so the part # 90566574 is correct I guess. I think any 99-01 ECM/ECU will work after programming it to the car correct?

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oh, do you think the ECM may have a relay or fuse and gone bad...any ideas where it is located?

RippyPartsDept
01-26-13, 01:17 PM
the fuse block cover has a legend that says what's what
owners manuals often also have the same legend (in case the fuse block cover gets lost i guess)

'99-'01 do show that they're the same
as for programming, whoever is doing the work will best be able to answer those related questions

the part number you mention (90566574) does not register as a good part number for me
if you're getting that part number off of the module that would make sense but not really help much
often the part number on the module does not match the parts catalog service part number(s)

you could use it to match other '99-'01 ecms ... but i think they're all the same unless you've got an export engine/vehicle

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and again, with a VIN we can take some of this guesswork out

retho78
01-26-13, 01:27 PM
okay, thanks. How about this part #9119539? Is that what you had previously?



Thanks.

RippyPartsDept
01-26-13, 01:31 PM
that is the one that i think is the export

really we just need the vin

retho78
01-26-13, 02:24 PM
okay, thanks. I'll try to get it tomorrow.

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I just found this part online Cardone 77-9101 (remanufactured ECM) for the 2001 Catera. Any clue if this is the right one or any good?

RippyPartsDept
01-27-13, 10:56 PM
no clue... never heard of an aftermarket ecm being remanufactured... i guess it's possible, and i'd be interested if it worked

retho78
01-28-13, 09:38 PM
Me either until I saw it on different websites and selling for around $230 and up.

retho78
01-28-13, 11:34 PM
Another update, car is still running a little rough and I think it's the throttle body and going bad. I did some cleaning of throttle body and after that it's running a little better but still RPM varies a lot. I turned off the CEL but it came back on again today and it's showing O2 sensors, bank 1 sensor 2 and bank 2 sensor 2 and no misfires. I ran a live data mode test with my code reader and it's reading the data for the O2s so not sure why the CEL comes on with O2 codes again and again.


Could a bad throttle body cause the O2s to act up? Any ideas?


Thanks.

RippyPartsDept
01-29-13, 10:21 AM
i just sell the parts, to tell you the truth....

it sounds like you could really use a FSM (factory service manual) ... they can get a bit expensive if you buy them new but they basically pay for themselves after using them once or twice

retho78
01-29-13, 10:28 AM
I do have a used one and will look into it ....hopefully find more info on the O2 issues.