93fdtwint

I just got my RX7 back from the body shop and this is my first time dirving it( ever)
the car iddles fine and drives ok under normal conditions but as soon as i punch it it takes me to like 3k or 4k rmps and starts bogging and back fires. I noticed my first cat gowing red so upgraded my exaust system with an HKS system. I eliminated the second CAT and kept the primary one. I took a ride and it still does the same thing. What could it be. please help

FDZero

iTrader: (10)

search "3K hesitation."

trainwreck517

iTrader: (1)

Wait, so you noticed the precat was glowing red, you upgraded the exhuast. Got rid of the main cat... but still kept the Precat?

If so then I think that the precat is cloged and causing excesive back presure causing your car to bog.

Try replacing the precat with a down pipe and see if that helps.

If its just a slight hesistation around 3-4k for a second, then drives fine under boost, check chassi ground.


Hope that helps.

tiger18

iTrader: (1)

thats so funny sorry,,,,i cant help it,,, thats like saying my coolant warning light was on so i changed the front tyre

93fdtwint

Sorry if this sounds funny to you tiger but the reason why I asked the question is because I had no idea what could be causing this problem. I do know that if the Cat conv is glowing red there could be a chance that one of my cats is clogged. so I upgraded my exaust system and eliminated one cat, how does that relate to your coment? If I was an expert on RX 7s believe me I would not be looking for answers I already know, and much less coments like yours.
Also when I upgraded my Exaust system I noticed there was a hose going to my stock exaust but my new system did not have an inlet for that hose. what do I do with it?
thanks 517 I will try eliminating my pirmary cat witha DP and see if that helps. Thanks for your advise.

tiger18

iTrader: (1)

sorry 93fdtwint,,,, sounds like your pre-cat has collapased and blocked itself up (its holding back the exaust gas escaping the engine,,,, the pre-cat failure is a common one for this car and thats why normally its the first mod most people do),,,, the pipe which was going to your main cat is for the air pump (the air pump blows air into the cat to dilute the exaust gas and give u a better CO level, so that your car will pass emmisions tests)

now mate if you have removed the main cat and you are about to bin the pre-cat,,,,,,u better start doing some major reading about boost spikes and boost creep relating to the exaust system (because removing both cats can lead to boost problems and engine failure (BANG"!))

93fdtwint

I checked the pre cat and it looks fairly new, how can I know if it's bad or not. Do you have any suggestions on a HP precat replacements( who has the best and what they run for). I was gonna just run the DP but now I'm thinking about it twice, last thing I want is for my engine to detonate

WolfpackFD3S

The best thing I think for you to do is get a downpipe (no one makes a aftermarket precat replacement to my knowledge). Plus the precat is bad, so you don't want one anyways, look up reliability mods and you will see what you need to do. So you don't run into other problems, get rid of the midpipe you put on and get a high flow cat. Read the newbie FAQs, all this info is in there.