Quick question on 99 C4 with 1K miles on Reman...

Wife driving home from work in commuting traffic and the 'check engine' light comes on. No issues while driving it. Get it home and read the following OBDII code: P040 Catalyst Efficiency Below threshold Bank 1. REset the code, spirited test drove - no light. Could that be an indicator of a 'going bad' cat??? Also yesterday: while standing behind the car yesterday morning when wife started it cold a pretty good puff of blue smoke from passenger-side exhaust and some residual puffing when she putted away. When she called me with the 'engine light' I immidiately thought worst case and drove to meet her and then swapped cars. I could find any ting weird except the light. Oil pressure went to about 3 bar a 5k rpm. No vibes, sounds or anything. She followed me and I floored it a couple times and she said blue smoke came from the passenger exhaust each time - good power when floored BTW . When we got home I checked the oil level several times and on the weird dip stick business end it appears that the oil level comes up almost above the cylindrical plug at the top of the bulbous level indicator area. Oil appeared clean though. Tells me that it may be a quart or two overfilled??? Have not drained a couple quarts yet to recheck the smoke issue. BTW: it did not smoke when sitting in idle in the driveway nor when and revving it in idle (I watched and she revved - maybe she didn't rev it enough???). One last OBTW: brake pedal is a little soft and ocasisonally when I drove it in stop & go commuting traffic the other morning I caught a glimpse of the the 'brake fluid level low' light quickly flickering on then off - almost imperceptibly. Fluid is actually 'high' when checked - I suspect brakes had bad flush or air in the lines. Plan to pressure bleed - any other ideas while at it? thanks in advance for your thoughts! Yes - I used the 'search' function for 45 minutes on the 'smoke issue' last night (Also/also: notice that the illuminated bottom displays in the dash gages do not extinguish for about 5 minutes after shutting down the car last nite. Tried it a couple times, same thing. Checked manual - not sure it mentions this - any ideas for the intellectually impaired???)

I hope that reman engine was from a dealer and has 2yr warranty!

Blue smoke from the exhaust is the tell-tale of oil in the cylinders. However, are you SURE it's blue? Double check on that, it could be white. I'm not aware of bad cat's causing blue smoke. Perhaps oil in the cylinders is affecting the cat and that is causing the engine light. Let the car sit for an hour and turn the ignition to the first position and look at the electronic oil indicator. Then check the dipstick. If your readings confirm as high an oil level as you indicated then DONT DRIVE THE CAR. Drain the oil, check it for water, coolant, metal or anything else out of place. Then change it with the correct amount and see if the whole issue was caused by incorrect oil level.

If the Reman engine is from a Porsche dealer and is still within the 2 year warranty, I'd give them a ring on Monday morning.

First thing I would do if the oil was up - is drainn it and re-fill to propper level or BELOW Cat might be separate issue, or relatedn get rid of the blue smoke, it might not return. Lights (odometer) stay on a while. Lock the car and it will "know" to shut them down Contact whoever is responable for the motor-dont mention oil was high

Firstly, I would follow the procedure outlined in your OM for checking the oil level. If you determine you need to remove any oil, without doing a full drain and refill, you can remove the oil filter housing and remove ~1qt that way.

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has been emitting that error code now for probably the last 40K miles (has 222K miles on original converters). Code usually more likely to appear if I drive car for short trip then park car then an hour or two later start car and resume driving. Colder days also contribute to the likelihood code will be registered. I'd leave this P0430 thing to look into at a later time. Smoking most likely normal -- absent any other engine symptoms that can signal AOS failing. Smoking can be exacrebated by engine being over filled with oil. This -- short version -- results in the crankcase fumes routed to intake to be burned containing more oil vapor (tiny oil droplets) and during normal engine running this is not enough to create visible oil smoke. But under some conditions this coats inside surface of intake manifold with oil and if engine shut off then allowed to sit this oil will drain down and into combustion chamber or puddle on top of closed intake valves. When engine started this oil of course is burned and given the amount of oil -- still very small -- oil smoke upon engine start the result. Oil smoking should be of short duration just moments and engine should not otherwise exhibit any untoward behavior. If it does, AOS can be bad and this must be looked into promptly. If you want with engine dead cold remove oil filter housing and dump oil into clean pan. Look for any signs of water (coolant) in oil. Coolant in oil can cause oil level to increase. If no signs of water/coolant in oil, reinstall housing. If you want to remove excess oil from engine, start engine, let idle a minute or so. Then shut off engine and remove filter housing again, dump out oil, reinstall, same as before. Using this tech. to remove excess oil from engine repeat process several times until you have removed the estimated amount of excess oil. Say a quart or so. Last time, I'd be inclined to use new oil filter and new o-ring. Or open drain plug just enough to let oil dribble out around plug into clean oil drain pan. Drain a quart or so out. Be sure to properly retighten oil drain plug. Not as much in favor of this cause I don't like reusing drain washer ring. As with oil filter oil check oil in pan for any signs of water/coolant. Not sure how to do this with 99 996 but if oil overfilled I'd do oil change draining old oil out and then refilling engine with proper amount of fresh oil. If oil/filter service done just recently no need to change filter. If oil overfilled at place you had car in for oil/filter service I'd seriously consider finding another place to take car for oil/filter services. If you find signs of coolant/water in oil or oil in coolant or engine exhibits other untoward behavior I'd have car flat bedded to dealer and have this checked into. Sincerely, Macster.

Changed the oil - with engine hot the level is between min and max on the stick. Will wait and see if this is the oil smoke puff on start and WOT events. Maybe (hopefully) excessive oil-richness overtaxed the cat and the O2 sensor and system reported it as a cat problem on that particular bank??? I talked to the engine installer and he is ready to look at it on Monday. All other fluids were perfect - no cream in the cap syndrome either. I like the little flexi oil fill tube - how cool is that! Update - seems like it was overfilled by over a qt at least. No problems driving today - will try it again tomorrow. I went ahead and drained the whole sump and refilled with clean M1 0-40W.

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error code. Probably just a weak converter weak cause it is wearing out. My Boxster has had not one but two AOSs go bad and neither time did Ecu emit a bad converter error code even though in both cases towards end engine was smoking like nobody's business. At that point I was aware of risk and shut engine off and didn't allow it to be started until after AOS fixed. Shortly after 1st AOS replaced did track down and replaced a bad O2 sensor. Coincidence. I've "resurrected" the bad converter by just before oil/filter service running two tanks of gas through engine with gas treated with Techron according to directions. Faced with emissions test and not wanting to spend over $1000 to have new exhaust manifold with converter installed in place of old one. Even looked into buying a used one and installing it myself but was cautioned by tech that almost invariably one sometimes more than one exhaust manifold bolt will snap and have to be drilled out and hole fittted wtih thread insert. This doesn't scare me directly but I have no place to work on car -- I take cars to work on weekends and do oil/filter services -- but can't risk a service/repair that could see the car ending up undrivable cause car would be in way at work. My advice is to run two tanks of gas treated with Techron as per directions through engine, then drain oil and refill with new oil. The Techron will help remove intake valve, combustion chamber, and exhaust valve and O2 and even converter deposits that could contribute to the P0430 or other O2 related error codes. Then drive car and see what happens. Sincerely, Macster.

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I will try the Techron - I have a case of it in the garage that I got from Costco last year - just looking for a reason to use some!

Quotes source post: 6687708

I will try the Techron - I have a case of it in the garage that I got from Costco last year - just looking for a reason to use some! Even though this engine is relatively new...