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Adding to this description I wrote a few weeks ago....

"I was driving it the other night not fast just normal and I felt it lagging pretty bad like it didnt want to idle any higher than all of a sudden, I stopped at the traffic lights like normal and pulled off from them and the car struggled to even move. I pushed the peddle all the way in than all the way out. Nothing! It moved but not very fast or even above 20km/h. It was like dying on me I swear. I was so worried cause I dont know what it was.. Its happened once before yet ive only had the car what like two weeks. I turned the car off straight after it lagged like that for about 10 minutes and it was fine but I know it wasnt normal. Hate stressing bout it :("

To add to that, it happened again the day before yesterday. I thought it was stuck in snow (the button) well its the car. If im driving the car, nothing goes wrong but if I just sit there on the spot in drive I can hear and feel this noise coming from the engine.. It sounds like thudding noises. I rev it so it goes away but comes straight back. After a few minutes of that happening is when the car will lag on me. It does it when the cars hot or just turned on, doesnt matter.. What the hell is it? Im thinking something to do with the gear box like the peddle slipping or something.. (its an automatic, non turbo) can anyone help?

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So that could be one thing, what else? Its only done the lag 3 times but that noise that the car makes before the car lags is almost everytime I pull up at the lights. The car sounds agry lol. But thanks for your reply, at least you have :rolleyes:

i'm sorry but to me a "blown" catalytic converter would not cause intermittent trouble like this. A "blown" catalytic converter would be constant. Also a "blown" catalytic converter would make the car seem underpowered but not down right unusable, and overcome by turning the car off then on. I'm a little lol about about this catalytic converter idea to be honest. There is zero logic in that. Maybe its the intercooler lol?

My 2 bob is that it sounds more like an electrical problem. What exactly i don't know. But electrical problems are often intermittent like this.

Well maybe the catalytic needs to be replaced as in its times up.. I wouldnt know but so far its the closest thing to what may be wrong.it effects the idle and the revs so i though gear box troubles. I fix one thing than another problem occours... I just want it to run great with not alot of attention. Also I just want to know, will this kinda thing if left untreated get worse?

a blown catalytic converter makes the car close to unuseable.......

if a piece of the inside comb breaks off, and actually blocks the majority of the inner matrix, it will stop all exhaust flow.

you will have no power and be forced to drive home on light throttle to even get anywhere.

im not saying it is, but its an easy diagnosis, drop your exhaust from front cat, and see how it looks inside.

but if it makes a rattling noise, it sounds to be mechanical.

+1 to the film clip, or a sound clip. it might help more :)

if it's the cat then can you explain why it would go away after turning the car off for 10 minutes. Again, a dead cat would give constant power loss if blocking exhaust, and in some cases a power increases in fact since the cat is a restriction to flow in the exhaust.

a few questions to original poster:

When you put peddle to floor when this is happening, does the engine actually rev out but car doesn't move, or do revs not climb at all? I don't think you've told us that.

+1 for video also.

I still think it's electrical

spark plugs

air flow meter

throttle position sensor

coil packs

etc....

when my cat blew, it gave a constant power loss above 2k rpm, below that it would drive sluggish, but the car could still accelerate.... till 2k rpm

when your cat blows, it will veeeeeery rarely blow the entire comb out, mine blew about 1/5th out and it shattered, and those shattered pieces would clog up the rest of the comb.

when turned off, those pieces fell into the matrix so the comb was not clogged no more. but after turning it on, it only took about 10 seconds tho till it was clogged again.... so i guess those 10 mins are a bit long.

oh yeah, +1 about asking those extra questions, haha i was just in debate mode :P sorry

Ill try get a video or something but when I want it to happen so I can tape it, it doesnt lol and when I dont want it to it does lol.

And with the revs, ill have a look when it happens next time and tell you. I cant remember :wacko:

if it's the cat then can you explain why it would go away after turning the car off for 10 minutes. Again, a dead cat would give constant power loss if blocking exhaust, and in some cases a power increases in fact since the cat is a restriction to flow in the exhaust.

a few questions to original poster:

When you put peddle to floor when this is happening, does the engine actually rev out but car doesn't move, or do revs not climb at all? I don't think you've told us that.

+1 for video also.

I still think it's electrical

spark plugs

air flow meter

throttle position sensor

coil packs

etc....

Its my exhauast raddling.. Thats whats making those noises, ok so I figured out the noise but how come when that happens for a while, the car will lag.. So something to do with my exhaust.. Phew lol

hmmm, dont forget, sometimes noise and the problem arent necessarily related. might just be a loose bolt on your exhaust making that noise.

best thing besides going straight to a mechanic and plowing out money is getting someone you know, friend or family whos car minded (mechanical wise) just to look at the basics for you. like your muffler etc :)

  • 4 weeks later...

The same thing happened in my R33 - turned out it was actually some dead coil packs. Upgrade to Spitfires if you can and that should solve the problem.

So you are recommending he spends ~$500 on a set of coil packs because it "might" be the problem......

Coil pack issues normally present under load around 5000 rpm, not at idle....

How are you going with those 'racing tyres'? :blink:

I had the same issue with my old R33 - it was the cat, in my case it had fallen off from a poor install.

Just had the same symptoms appear with my girlfriends S15, huge loss of power and at some times it would even sound like a rexy. Hers was coil packs - just replaced all.

If I were you, i'd go in the following order -

1) Check the cat, if your not comfortable - go to an exhaust shop and have it done

2) Check your spark plugs - when were they last changed? Are the correct plugs being used?

3) Check your coil packs - see if someone on the forums or around your area can lend you a set, or put up a WTB for a used set and if this fixes your issue, maybe then look at grabbing some splitfires or brand new genuine nissan ones if you can afford it.

Come to think of it, I also had the same issue with my Evo. And when I checked the spark plugs, they were wet and rusted from the last owner probably cleaning the engine with a high pressure cleaner. So yeah, plugs are obviously key to the puzzle aswell.

So hopefully my last post above will help u out in some way.

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