KingBonacci

My car has been progressively running worse and worse over the last few weeks and I'm sure the 20 degree weather isn't helping much.

Starting it has been taking unusually longer than normal, especially cold starts or the first start of the day. It cranks over for a while until it will start, barely. Once started it will run for 10-20 seconds and will stall, turn ignition off and start again, it will fire up and idle but very roughly, giving it gas during this time sounds very rough and sputtery. Even after it's mostly warmed up and I'm driving around lower rpm's seem sputtery and slightly sluggish. Once it's fully warmed up everything seems fine, all the power is seemingly there. So yesterday I go to leave work and start the car (cold start) and it goes through the same start rough to a idle then stall, go to restart only this time it's just cranking over and over and not starting. I tried several times to get it started and it just didn't want to start. I tried one last time and it started but barely, idle got very rough and a threw a flashing CEL and then went off. I started driving home and the CEL came on again (not flashing this time) and just stayed on.

Got home parked it and checked the CEL with my ODB2 reader. It showed a P0420 wich I have had randomly come and go on it's own for the last two years even though there were no bad symptoms, noticeably anyway.

It also showed a P0302 cylinder 2 misfire which is the first time I have gotten that.

I took the wife's car to work today, after work I got home and went to start the RX8 just for the hell of it and it did pretty much the same thing, fired up ran 10 seconds or so then stalled, turned ignition off started again and it ran very rough, pressing the gas makes a really unusual sputtery rough sound. Which seemed to stop after fully warm.

Things I've done in the last year:

new NGK plugs and wires

new ignition coils

new battery

cleaned MAF

cleaned ESS

reset ECU (20 brake stomp method)

car has 90,xxx miles on it

I took it to a mechanic a few months ago I've used for the car in the past and had him do a PSI compression test, I can't remember the numbers but he assured me it was in safe zone. And he added the car still felt like it had all it's power.

The car is all stock except my Borla cat back exhaust. Always keep up on oil changes, always use premium gas, ALWAYS wait for the temp needle to register some heat before driving it (even is summer). I really take car of the car but realize it's gaining in mileage and could be approaching it's slow demise. I plan on keeping the car forever so I am in for the long haul with it, if it needs a new engine I will eventually give it one.

I guess what I'm wondering is, could this just be a bad cat? How worth is it to just gut it. I don't want to lay out the cash for one at the moment. Would a ECU reset help me out here? Should I check all the plugs? What else should I do at this point?

BigCajun

iTrader: (1)

Definitely inspect the cat. If it's broken up, cracked, clogged or melted, then gut it.
I would check that first.

ShinkaEvo

iTrader: (3)

You had P0420 for awhile and you didn't bother to take care of it...for 2 years...
Worst case, your motor went down to hell with the cat.
Best case, faulty sensor.
We'll never know what exactly happened until you take off the cat and inspect it or bring it to a rotary shop for proper diagnose.
GL.

KingBonacci

Well when I first had that code pop up I tried a few things one of which was changing the gas cap which I don't think did anything. The code would just go away on it's own, for months at a time, sometimes if I drove really hard it would pop on but would go away in a day or so then be off again for months so I didn't think to much of it, maybe a faulty sensor at best. My thoughts were if the cat was that bad the code would stay on. This is the first time in maybe 7-8 months I had that code pop up.

KingBonacci

NOTE: This an update to a previous thread I started. Which can be found here

https://www.rx8club.com/series-i-tro...-p0302-250028/

Update. My car has been sitting the last couple months unable to start. It doesn't really sound like it is turning over properly either. Doesn't even sound like it's turning the motor over at all. If you read my previous post you can see the symptoms it was having up to this. Finally one morning it just wouldn't start and now has just been sitting. Before having it towed to a mechanic there might be some things I could try before spending any cash.

Here's a few things I was thinking it would be.

Bad fuel filter/pump

Bad alternator

Bad starter.

The battery is new and I've tried starting it with jumpers as well and still nothing. I'm just hoping it's not dead engine and it's one of the easier things.

The car is a 2004 MT GT 6spd 90k miles on it

Is there anything I can test for before taking it for a compression test?

Here is a short video of me trying to start it

Williard

iTrader: (18)

#1 Which starter do you have. #2 When were the Coils plugs and wires replaced? That really just seems as if it's a dead battery. If the alternator was bad, when you jump started the car, it would have started off of the battery power, then died once the battery power is depleted. When you turn the car to the ON position before starting, do you hear the fuel pump kick in?

Williard

iTrader: (18)

Ok i just read through your previous post. So first off https://www.rx8club.com/series-i-tro...nk-1-a-153127/ Read that and tell me why it's a good idea to ignore this code. You realize your CAT is probably blocked, melted, broken. Whatever you would like to call it. Do you understand what that does to these cars? You basically slow roasted your engine. Now did your plugs or coils or wires fail? Honestly, i would replace them AGAIN because you ignored this code because you didnt' notice any symptoms. Would you like to know a symptom? Your car throwing that code. You either need to throw a midpipe on or gut your CAT NOW. While your at it as i said replace your coils plugs and wires again. You'll be lucky if the motors not shot. And even if it's not, how much damage did you inflict before it couldn't do it anymore.

KingBonacci

I believe it's the stock starter, I've tried charging the battery over night and starting it but still just keeps turning over like in the video. Also trying to jump start it gives the same result. The coils, plugs and wires were done a year ago. The only reason I didn't mess with the cat is because everything I read about failing cat would result in power failure and constant codes. I never lost power and the code would just come and go and sometimes stay off for months.

So is my next step to take off the cat or try and replace battery or could it be a weak dying starter?

BigCajun

iTrader: (1)

Misfires kill cats quickly, inspect it to eliminate that possibility first. If it's good, then I would get the starter checked.

KingBonacci

Is there a way I can check the starter to see if it's failing or not?

Williard

iTrader: (18)

Yea, remove take to autozone or advance or oreillys. They have a bench test.

Karack

1) the engine sounds extremely flooded or dead, hopefully just flooded from sitting.

2) your battery or starter or possibly both are flat, charge the battery, test it, jump start it, whatever to be sure you have good cranking amps which you don't have right now. check the battery voltage, if it's less than 12.6v after charging and/or under 9v while cranking then replace it.

3) do the deflooding procedures when the car is actually cranking at a decent speed, like twice what it currently is..

4) or just pull start the bitch and address the above after.