Will do, thanks for the help.

 

Stuart, i think you might be onto something with the fuse for the cams. i noticed the other day that the usual chaotic symphony of awesome noise that usually kicks in when the cams open up at 4500 rpm isn't so pronounced lately, if happening at all. i'll check out the fuses when i get a chance. tried to last night but they're hard to check while plugged in.

haven't had a chance to check for exhaust leaks, but i'll do that, too.

 

realized i haven't updated this... i checked the fuses, they're all fine. here's what i'm thinking:

my car has the Power Pack. for those that aren't familiar with it, it's a factory option that gives you different intake air boxes that have flaps built into them. at higher RPMs, the flaps open to let in more air. the ECU is remapped accordingly, providing extra fuel to compensate for the extra air. result is an extra 20 hp and 7 lb-ft tq. the flaps on the intake boxes are opened and closed by solenoids that activate (open) based on vacuum, which comes from a vacuum line that is tapped into the intake manifold (also included in the Power Pack).

the previous owner of my car installed the Power Pack, but then modified the standard air boxes by drilling holes in them. he re-installed them and capped off the vacuum lines. the idea is that there is always more air going to the engine, not just at higher RPMs (same concept as a high-flow filter, cold air intake, etc - more air means more power).

however, i think the ECU is throwing a tantrum because it's expecting an increase in air once the flaps are supposed to open. but the extra air never comes (it was already there the whole time due to the modified standard intake boxes being there in place of the Power Pack intake boxes, so there isn't a change in air flow from low-to-high RPMs), but the extra fuel does come. so the car runs rich (as seen on my dyno plots on the first page), and i get a CEL.

so i'm having the Power Pack intake boxes re-installed on Friday (along with having a squeak hunted down, see my other thread for that), and having the CEL cleared. hopefully that'll solve the problem. if not.... i'll keep hunting.

this is the hard part of playing with niche-market cars, not much out there for these odd little experiences! oh well, it's half the fun!

 

i just replaced the Swiss cheese'd standard air boxes with the unmodified Power Pack air boxes (this was not the 5-minute job that it is on every other car ever built ever). while at it, i had a smoke test done on the intake manifold and vacuum lines and whatnot - no leaks. lifted the car up and looked at the exhaust - a couple leaks. so hopefully with the exhaust leaks fixed and the unmodified air boxes back on, the CEL will stay off. btw, CEL codes were P0420 and P0430 - cat inefficiencies on both banks.

the air boxes were more of a pain that my mechanic and i were expecting, so we didn't get around to dealing with the e-brake squeak.

 

CEL is back, so the hunt for the cause continues. next i'm going to try pulling the RSC 200-cell cats off and putting the stock ones back on. if that isn't it... i have no idea!

 

Sorry to hear, thats a shame. I really doubt its the CAT's as mine have never thrown a code.

If you are going through with pulling them out yourself, below is the thread on how I installed mine.

https://www.6speedonline.com/forums/...ats-today.html

 

Did you go through a number of start/driving/stop cycles to give the ECU a chance to gather enough data on the "new" configuration to determine what's normal now? It may take 3 - 5 cycles (plus miles) to clear your CEL.
Just a thought before you dig into changing the cats.

 

a buddy of mine came up with an interesting idea... he said there might be too much heat, causing the o2 sensors to have skewed readings. he said he's seen this on other cars. i hadn't heard of this before, but this is a new problem for me that i haven't seen on any other car i've worked on. he recommended getting some washers made of heat-resistant metal and using them as a sort of insulation between the cat and the sensor. anyone ever seen or heard of this?

i had the CEL cleared after performing all the work. the CEL returned the next day.

thanks! i'll be swapping them out this coming weekend if i have time.

 

The only thing I can see with these faults is the cats not converting by-products correctly..OR they or o2 sensors have to much oil in them..if your PCV dumped out and drenched the cat/sesnors with oil..cat and sensors are useless. But this would have shot out grey smoke from the tails and you would of had to replace the PCV to correct the concern..that's one possible case, did you ever happen to have this ocur?

The power pack air boxes..sry didn't see this before, but it will not cause the car to run rich even if the valves do not open. The engines air is monitored by the MAF sensors. Depending on the amount of air monitored is measured to the needed amount of fuel. If you are running rich with the RSC cats..do as your about to and swap out the RSC's for the originals, and see if the fault returns in the time frame you usually flag the fault..one thing though, if the fault does not return..DO NOT RUN LIKE THIS FOR LONG, at least untill you verify the fault is only with the cats and not the car that fried the cats. To give you a better understanding of this fault, PCM see's the cats not converting the harmfull by-products to lesser harmless by-products..this minimum spec of metered by-products is still 2 high once it reachs the aftercat sensors...so either the cat is drenched in oil, or sensor is drenched in oil, or there is a PIN SIZED hole in the weld or leak at the header to cat flange, or high fuel pressure has fried the cats..you will get these codes. ..was there any other faults besides p0420 and p0430,
any of these?
• Misfire (P0300 - P0308)
• H02 sensors (P0133/P0135/P0141/P0155/P0161)
• IAT sensor (P0112/P0113)
• ECT sensor (P0116/P0117/P0118/P0119/P1116)

do you have high oil consumption, do you know the full history of the car, as could there of been another tune done that was not from aston?

Sy it's a lot of questions..just trying to get a better undertsanding

 

nope, no other error codes other than P0420 and P0430. the last service on the car was done at a dealership, about 24k miles on the car and the only thing they noted was the leaky AOS.

here are the original primary o2 sensors. i had them replaced in my first round of troubleshooting the CEL.



sorry, i have run out the door 5 minutes ago so let me know if that doesn't help answer your questions.

 

could such a small exhaust leak between the headers and cats cause the CEL??? if so, that might be the culprit. my mechanic and i got under the car and checked the exhaust while replacing the airboxes, and we did find some leak points. he re-installed the clamps on the front of the cats, but the CEL came back the next day. he said we could pull the cats and re-install them with a paste (can't remember the term he used) that is made to seal exhausts. if a tiny leak here can cause CELs, then this might be the problem!

are there gaskets that can fix this or should i have him pull the cats and re-install them with the sealant?

 

Nothing after the cat will cause this, only leaks before the cat or from the actual cat it's self..clamps I believe you talking about are after the cat..so no they will not cause this..but the gasket betwenn teh header and cat will for sure..just takes a PIN sized leak

 

just switched back to the stock cats. first off, I MISS THE NOISE!!! the stock cats make the car sound so... civil and mundane... the RSC cats make a huge difference to sound, a big improvement in my opinion.

the RSC cats look fine, there's no oil or buildup or anything like that. but i'm trying to hunt down this CEL and i'm looking at any and all possibilities. hopefully this will fix my CEL, because my current tab for all the stuff i've tried is now up to $1307

i talked to RSC a couple months ago and they said if the cats really were the problem, they'd replace them for me (awesome customer service!). besides, this CEL is holding me back from getting a tune, and i'd like a bit more power haha.

anyway, took a couple shots for comparisons since i had them sitting next to each other.

stock and RSC


stock


RSC

 

okay, it wasn't the high-flow cats. it took a few weeks and several hundred miles, but the CEL came back on this morning. i'm starting to lean toward the fuel system being the cause. maybe it's related to the stalling issue and line in the fuel tank that was discussed in the other thread.

big thumbs up to Stuart and RSC for standing behind their products and offering to swap mine out with a new set.

 

The line in the tank will run you a rich mixture fault..you could get p0420 and p0430, but will also flag the rich misture faults, could also get vapour valve not closing faults..all with just he fuel tank hose concern.

In your case, you have no lean/rich codes, just catalyst efficiency on "both" banks, which is not common..usually 1 of the banks when a concern happens...which is kinda stumping me being that I can't datalog anything to view..

This could actually occur if the downstream o2 harnesses had been mixed up and swaped some how..aka during a clutch change(hard to mess up but possible)...I've never had this on a Aston, but have on other brands, and if this happened it would give you the same/only faults you have(P0420 and P0430)...ECU looks at RH upstream and checks RH Downstream and compares, same for LH side..but if you swap the up or downstream harnesses..When RH upstream is checked to compare with it's dowstream and the LH harness is hooked to the RH Downstream...you will flag cat efficiency on both banks. if the upstreams are swapped you could run rich/lean and get cat efficiency faults.

If you have a datalog tool this would be easy to find out, if not a OBD II scanner can work..unplug 1 of the sensors and start the car..see what fault you get for which bank..do that for all 4 sensors and verify there position...otherwise your going to have to visit the dealer with the original cats in place..advise them about the o2s just being replaced and let them get deaper datalogging..any other info/diagnoses would be just a guess